Skip to main content

Full text of "The depths of the sea: an account of the general results of the dredging cruises of H.M.SS. 'Porcupine' and 'Lightning' during the summers of 1868, 1869, and 1870, under the scientific direction of Dr. Carpenter, F.R.S., J. Gwyn Jeffreys, F.R.S., and Dr. Wyville Thomson, F.R.S."

See other formats


LIBRARV 

UNIVEJiSITY  OF  CAUFORNIA 
DAVIS 


Digitized  by  the  Internet  Archive 

in  2007  with  funding  from 

IVIicrosoft  Corporation 


http://www.archive.org/details/depthsofseaaccouOOthomrich 


C^iVi 


'J- 


T^O/M^OsT 


THE 


DEPTHS   OF   THE   SEA. 


THE 


DEPTHS  OF  THE  SEA 


i 

%  AN  ACCOUNT  OF  THE  GENEKAL  RESULTS 

I  OF   THE 

DREDGING  CRUISES  OF  H.M.SS.  'PORCUPINE'  AND  'LIGHTNING 

DURING  THE  SUMMERS  OF  1868,  1869,  AND  1870, 

UNDER  THE  SCIENTIFIC  DIRECTION  OF 

DR.  CARPENTER,  F.R.S.,  J.  GWYN  JEFFREYS,  F.R.S., 
AND  DR.  WYVILLE   THOMSON,  F.R.S. 


BY 


C.    WYVILLE    THOMSON, 

LL.D.,  D.Sc,  F.R.SS.  L.&E.,  F.L.S.,  F.G.S.,  Etc 

Regius  Professor  of  Natural  History  in  the  University  of  Edinburgh, 
Awl  Director  of  the  Civilian  Scientific  Staff  of  the  'Challenger'  Exploring  Expedition. 


WITH     NUMEROUS     ILLUSTRATIONS     AND     MAPS. 

LIBRARY 

UNIVERSITY  OF  CALIFORNIA 
DAVIS 

MACMILLAN    AND    CO. 

1873. 


LONDON  : 

R.    CLAY,   SONS,   AND  TAYLOR,   PRINTERS, 

BREAD  STREET  HILL. 


TO 

MADAME     HOLTEN 

IN 
GRATEFUL    REMEMBRANCE    OF    THE    PLEASANT    TIMES 

SPENT    BY    HIMSELF    AND    HIS    COMRADES 


GOVERNOR  S   HOUSE   IN  THORSHAVN, 


BY 


THE  AUTHOR. 


PEEFACE. 


At  the  close  of  the  Deep-sea  Dredging  Expeditions 
which  had  heen  undertaken  hy  the  Admiralty  at  the 
instance  of  the  Council  of  the  Royal  Society  during 
the  years  1868,  1869,  and  1870,  it  was  thought  right 
that  those  who  had  been  entrusted  with  their  scien- 
tific direction  should,  in  addition  to  their  official 
reports,  lay  before  the  general  public  some  account 
of  their  proceedings  with  the  objects ; — first,  of  show- 
ing, if  possible,  that  the  value  of  the  additions  which 
had  been  made  to  human  knowledge  justified  the 
liberality  of  Government  in  acceding  to  the  request 
of  the  Council  of  the  E>oyal  Society,  and  placing 
means  at  their  disposal  to  carry  out  the  desired 
researches;  and,  secondly,  of  giving  such  a  popular 
outline  of  the  remarkable  results  of  our  work  as 
might  stimulate  general  interest,  and  induce  those 
who  have  the  proclivities  and  the  opportunity,  to 
penetrate  farther  into  the  new  and  strange  region 
on  whose  borders  we  have  had  the  good  fortune  to 
have  been  among  the  first  to  encroach. 


viii  FREFJCE. 

It  was  originally  intended  that  the  general  account 
should  have  been  a  joint  production,  each  of  us  con- 
tributing his  part.  There  were  difficulties,  however, 
in  the  way  of  this  arrangement.  We  were  all  fully 
occupied  with  other  matters,  and  the  amount  of 
communication  and  correspondence  between  us,  re- 
quired to  carry  out  the  plan  of  joint  authorship, 
seemed  likely  to  prove  a  cumbrous  complication. 

It  was  therefore  decided  that  quoad  the  popular 
exposition  I  should  take  upon  myself  the  office  of 
'reporter,'  and  thus  it  comes  about  that  I  am  indi- 
vidually and  solely  responsible  for  the  opinions  and 
statements  contained  in  this  book,  save  where  they 
are  included  within  quotation  marks,  or  their  sources 
otherwise  acknowledged. 

Since  we  began  these  deep-sea  investigations, 
inquiries  have  come  in  from  all  quarters,  both  at 
home  and  abroad,  as  to  the  implements  and  methods 
which  we  employ.  To  supply  the  desired  informa- 
tion, I  have  described,  in  detail,  the  processes  both 
of  sounding  and  dredging;  and  I  hope  that  the 
special  chapters  on  these  matters — the  result  of 
considerable  experience — may  be  found  useful  to 
beginners. 

I  pretend  to  no  special  knowledge  of  physics,  and 
I  should  have  greatly  preferred  confining  myself  to 
the  domain  of  Biology,  my  own  proper  province; 
but  certain  physical  questions  raised  during  our  late 
explorations  have  so  great  importance  in  relation  to 


PREFACE.  ix 

the  distribution  of  living  beings,  and  have  of  late 
been  brought  into  so  great  prominence  by  Dr.  Car- 
penter, that  it  has  been  impossible  for  me  to  avoid 
giving  my  earnest  consideration  to  their  general 
bearings  on  Physical  Geography,  and  forming  decided 
opinions,  which,  I  regret  to  say,  do  not  altogether 
coincide  with  those  of  Dr.  Carpenter.  The  chief 
points  on  which  my  friend  and  I  '  agree  to  differ ' 
are  discussed  in  the  chapter  on  the  Gulf- stream. 

It  was  at  first  my  intention  that  appendices  should 
be  added  to  the  different  chapters,  containing  lists 
and  scientific  descriptions  of  the  animal  forms  which 
were  observed.  This  it  was  found  impossible  to 
accomplish,  chiefly  on  account  of  the  large  number 
of  undescribed  species  which  were  placed  in  the  hands 
of  the  experts  who  undertook  the  examination  of  the 
several  groups.  I  am  not  sure  that,  even  if  it  had 
been  possible  to  furnish  them  in  time,  such  lists 
would  have  been  altogether  an  appropriate  addition 
to  what  is  intended  merely  as  a  popular  preliminary 
sketch. 

The  metrical  system  of  measurement,  and  the 
centigrade  thermometer  scale,  have  been  adopted 
throughout  the  volume.  The  metrical  system  is  pro- 
bably familiar  to  most  of  my  readers.  In  case  the 
centigrade  notation,  which  comes  in  very  frequently 
owing  to  the  frequent  discussion  of  questions  of  the 
distribution  of  temperature,  should  not  be  equally 
familiar,   a  comparative    scale,   embodying   those   of 


C.  R. 


PREFACED. 

Fahrenheit,  Celsius,  and  Eeau- 
mur,  is  introduced  for  com- 
parison. 

My  various  sources  of  infor- 
mation, and  the  friendly  as- 
sistance I  have  received  on  all 
hands  during  the  progress  of 
our  work,  are  acknowledged,  so 
far  as  possible,  in  the  text. 
I  need  here  only  renew  my 
thanks  to  Staff- Commander 
May  and  the  officers  of  the 
'Lightning,'  and  Captain  Cal- 
ver  and  the  officers  of  the 
'  Porcupine,'  without  whose 
hearty  sympathy  and  co-ope- 
ration our  task  could  never 
have  been  satisfactorily  accom- 
plished ;  to  my  colleagues.  Dr. 
Carpenter,  F.Il.S.,  and  Mr. 
Gwyn  Jeffreys,  F.E^.S.,  who 
have  cordially  assisted  me  in 
every  way  in  their  power  ;  and 
to   the  naturalists   into  whose 

_  hands  the  animals  of  various 
classes  were  placed  for  descrip- 
tion and  study, — the  Rev.  A. 
Merle  Norman,  Professor  Kol- 

_liker,  Dr.  Carter,    P.E.S.,    Dr. 
oilman,   E.R.S.,   Professor  Martin  Duncan,  E.R.S., 


85 


80 


75 


70 


65 


60 


55 


50 


45 


40 


35 


30 


25 


PREFACE.  xi 


and    Dr.     Mcintosh,     for     information     courteously 
supplied. 

The  whole  of  tlie  illustrations  in  the  book — with 
the  exception  of  the  vignettes  of  Fseroe  scenery  for 
which  lam  indebted  to  the  accomplished  pencil  of 
Madame  Holten — are  by  my  friend  Mr.  J.  J.  Wild. 
I  need  scarcely  thank  him  for  the  admirable  way  in 
which  he  has  accomplished  his  task,  for  every  figure 
w^as  with  him  a  labour  of  love,  and  I  almost  envy 
him  the  gratification  he  must  feel  in  the  result. 
To  Mr.  J.  D.  Cooper  I  owe  my  sincere  thanks  for 
the  singularly  faithful  and  artistic  rendering  of 
Mr.  Wild's  beautiful  drawings   on  the  wood-blocks. 

On  the  return  of  the  'Porcupine'  from  her  last 
cruise,  so  much  interest  was  felt  in  the  bearings  of 
the  new  discoveries  upon  important  biological  geo- 
logical and  physical  problems,  that  a  representation 
was  made  to  Government  bv  the  Council  of  the 
Royal  Society,  urging  the  despatch  of  an  expedition 
to  traverse  the  great  ocean  basins,  and  take  an  out- 
line survey  of  the  vast  new  field  of  research — the 
bottom  of  the  sea. 

Eear-Admiral  Richards,  C.B.,  P.R.S.,  the  Hydro- 
grapher  to  the  Navy,  warmly  supported  the  pro- 
posal, and  while  I  am  writing  a  noble  ship  is 
lying  at  Sheerness  equipped  for  scientific  research 
under  his  wise  and  liberal  directions,  as  no  ship 
of  any  nation  was  ever  equipped  before. 


xii 


PREFACE. 


The  scientific  staff  of  the  '  Challenger*  are  well 
aware  that  for  some  time  to  come  their  rdle  is  to 
work  and  not  to  talk ;  but  now,  on  the  eve  of  depar- 
ture, I  think  it  is  only  right  to  take  this  opportunity 
of  saying  that  nothing  has  been  left  undone  by  the 
Government  to  ensure  the  success  of  the  undertaking, 
and  that  dire  misfortune  only  ought  to  prevent  our 
furnishing  a  valuable  return. 

C.  Wyville  Thomson. 

Edinburgh, 

December  2nd,  1872. 


CONTENTS. 

CHAPTER  L 

INTRODUCTION. 

The  Question  of  a  Bathymetrical  Limit  to  Life. — The  general  Laws  which 
regulate  the  Geographical  Distribution  of  Living  Beings. — Professor 
Edward  Forbes'  Investigations  and  Views. — Specific  Centres. — Repre- 
sentative Species. — Zoological  Provinces. — Bearings  of  a  Doctrine  of 
Evolution  upon  the  Idea  of  a  '  Species/  and  of  the  Laws  of  Distribution. 
— The  Circumstances  most  likely  to  affect  Life  at  great  Depths  :  Pres- 
sure, Temperature,  and  Absence  of  Light Page  1 


CHAPTER  II. 

THE   CRUISE   OF   THE   *  LIGHTNING.' 

Proposal  to  investigate  the  Conditions  of  the  Bottom  of  the  Sea. — Sugges- 
tions and  Anticipations. — Correspondence  between  the  Council  of  the 
Royal  Society  and  the  Admiralty. — Departure  from  Stornoway. — The 
Fseroe  Islands. — Singular  Temperature  Results  in  the  Fseroe  Channel. — 
Life  abundant  at  all  Depths. — Brisinga  coronata. — Holtenia  carpenteri. 
— General  Results  of  the  Expedition        Fage  49 

Appendix  A. — Particulars  of  Depth,  Temperature,  and  Position  at  the 
various  Dredging  Stations  of  H.M.S.  'Lightning,'  in  the  Summer  of 
1868  ;  the  Temperatures  corrected  for  Pressure       Page  81 

CHAPTER  III. 

THE   CRUISES    OF   THE    'PORCUPINE.' 

The  Equipment  of  the  Vessel. — The  first  Cruise,  under  the  direction  of  Mr. 
Gwyn  JeflFreys,  off  the  West  Coast  of  Ireland  and  in  the  Channel 
between  Scotland  and  Rockall. — Dredging  carried  down  to  1,470  fathoms. 


xiv  CONTENTS. 

— Change  of  Arrangements. — Second  Cruise  ;  to  the  Bay  of  Biscay. — 
Dredging  successful  at  2,435  fathoms. — Third  Cruise  ;  in  the  Channel 
between  Fseroe  and  Shetland. — The  Fauna  of  the  '  Cold  Area.'    Page  82 

Appendix  A. — Official  Documents  and  Official  Accounts  of  preliminary 
Proceedings  in  connection  with  the  Explorations  in  H.M.  Surveying- 
vessel 'Porcupine/ during  the  Summer  of  1869     Page  \2iZ 

Appendix  B. — Particulars  of  Depth,  Temperature,  and  Position  at  the 
various  Dredging  Stations  of  H.M.S.  '  Porcupine,'  in  the  Summer  of 
1869      Page  142. 


CHAPTER  IV. 

THE  CRUISES  OF  THE   '  PORCUPINE '  {continued). 

From  Shetland  to  Stornoway. — Phosphorescence. — The  Echinothuridce. — 
The  Fauna  of  the  '  Warm  Area.' — End  of  the  Cruise  of  1869. — Arrange- 
ments for  the  Expedition  of  1870. — From  England  to  Gibraltar. — 
Peculiar  Conditions  of  the  Mediterranean. — Return  to  Cowes.    Page  145 

Appendix  A. — Extracts  from  the  Minutes  of  Council  of  the  Royal  Society, 
and  other  official  Documents  referring  to  the  Cruise  of  H.M.S.  '  Porcu- 
pine '  during  the  Summer  of  1870    Page  197 

Appendix  B. — Particulars  of  Depth,  Temperature,  and  Position  at  the 
various  Dredging- stations  of  H.M.S.  '  Porcupine '  in  the  Summer  of 
1870 Page  202 


CHAPTER  V. 

deep-sea  sounding. 

The  ordinary  Sounding-lead  for  moderate  Depths. — Liable  to  Error  when 
employed  in  Deep  Water. — Early  Deep  Soundings  unreliable. — Improved 
Methods  of  Sounding. — The  Cup-lead. — Brooke's  Sounding  Instrument. — 
The  '  Bull-dog  ; '  Fitzgerald's  ;  the  '  Hydra.' — Sounding  from  the  '  Porcu- 
pine.'— The  Contour  of  the  Bed  of  the  North  Atlantic         . . .     Page  205 


CHAPTER  VI. 

deep-sea  dredging. 

The  Naturalist's  Dredge. — 0.  F.  Miiller.— Ball's  Dredge. — Dredging  at 
moderate  Depths. — The  Dredge-rope. — Dredging  in  Deep  Water. — The 
'  Hempen  tangles.' — Dredging  on  board  the  *  Porcupine.' — The  Sieves. — 


CONTENTS.  XV 

The  Dredger's  Note-book. — The  Dredging  Committee  of  the  British 
Association. — Dredging  on  the  Coast  of  Britain.— Dredging  abroad. — 
History  of  the  Progress  of  Knowledge  of  the  Abyssal  Fauna.     Page  236 

Appendix  A.  —One  of  the  Dredging  Papers  issued  by  the  British  Associa- 
tion Committee,  filled  up  by  Mr.  Mac  Andrew         Pa^e  281 

CHAPTER  VIL 

DEEP-SEA   TEMPERATURES. 

Ocean  Currents  and  th^r  general  Effects  on  Climate. — Determination  of 
Surface  Temperatures. — Deep-sea  Thermometers. — The  ordinary  Self- 
registering  Thermometer  on  Six's  principle. — The  Miller-Casella  modifi- 
cation.— The  Temperature  Observations  taken  during  the  Three  Cruises 
of  H.M.S.  '  Porcupine  '  in  the  year  1869,  etc Page  284 

Appendix  A. — Surface  Temperatures  observed  onboard  H.M.S.  'Porcupine' 
during  the  Summers  of  1869  and  1870 Page  329 

Appendix  B. — Temperature  of  the  Sea  at  different  Depths  near  the  Eastern 
Margin  of  the  North  Atlantic  Basin,  as  ascertained  by  Serial  and  by 
Bottom  Soundings      Page  352 

Appendix  C. — Comparative  Rates  of  Reduction  of  Temperature  with 
Increase  of  Depth  at  Three  Stations  in  different  Latitudes,  all  of  them 
on  the  Eastern  Margin  of  the  Atlantic  Basin         Page  353 

Appendix  D. — Temperature  of  the  Sea  at  diff'erent  Depths  in  the  Warm  and 
Cold  Areas  lying  between  the  North  of  Scotland,  the  Shetland  Islands, 
and  the  Fseroe  Islands  ;  as  ascertained  by  Serial  and  by  Bottom  Sound- 
ings            Page  354 

Appendix  E. — Intermediate  Bottom  Temperatures  showing  the  Intermixture 
of  Warm  and  Cold  Currents  on  the  Borders  of  the  Warm  and  Cold 
Areas    Page  355 


CHAPTER  VIII. 

the    gulf-stream. 

The  Range  of  the  *  Porcupine '  Temperature  Observations. — Low  Tempera- 
tures universal  at  great  Depths. — The  Difl&culty  of  investigating  Ocean 
Currents. — The  Doctrine  of  a  general  Oceanic  Circulation  advocated  by 
Captain  Maury  and  by  Dr.  Carpenter. — Opinion  expressed  by  Sir  John 
Herschel. — The  Origin  and  Extension  of  the  Gulf-stream. — The  Views  of 
Captain  Maury  ;  of  Professor  Bufi^ ;  of  Dr.  Carpenter. — The  Gulf-stream 
off  the  Coast  of  North  America. — Professor  Bache's  '  Sections.' — The 
Gulf-stream  traced  by  the  Surface  Temperatures  of  the  North  Atlantic. — 
Mr.  Findlay's  Views. — Dr.  Petermann's  Temperature  Charts. — Sources  of 


xvi  CONTENTS. 

the  underlying  Cold  Water. — The  Arctic  Keturn  Currents. — Antarctic 
Indraught. — Vertical  Distribution  of  Temperature  in  the  North  Atlantic 
Basin     Page  356 


CHAPTER  IX. 

THE    DEEP-SEA    FAUNA. 

The  Protozoa  of  the  Deep  Sea. — Bathyhhis. — '  Coccoliths,'  and  *  Cocco- 
spheres.' — The  Foraminifera  of  the  Warm  and  Cold  Areas. — Deep-sea 
Sponges.  —  The  Hexactinellid*.  —  liossella.  —  Hyalonema.  —  Deep-sea 
Corals.  —  The  Stalked  Crinoids.  —  Pentacrinus. — Rhizocrinus.—Bathy- 
crinua. — The  Star-fishes  of  the  Deep  Sea. — The  general  Distribution  and- 
Relations  of  Deep-sea  Urchins. — The  Crustacea,  the  Mollusca,  and  the 
Fishes  of  the  *  Porcupine  '  Expeditions    Page  407 


CHAPTER  X. 

THE  CONTINUITY  OF  THE  CHALK. 

Points  of  Resemblance  between  the  Atlantic  Ooze  and  the  White  Chalk. — 
Differences  between  them. — Composition  of  Chalk. — The  Doctrine  of  the 
Continuity  of  the  Chalk. — Objections. — Arguments  in  favour  of  the 
View  from  Physical  Geology  and  Geography. —Former  Distribution  of 
Sea  and  Land. — Palseontological  Evidence.  —  Chalk-flints.  —  Modem 
Sponges  and  Ventriculites — Corals. — Echinoderms. — Mollusca. — Opinions 
of  Professor  Huxley  and  Mr.  Prestwich. — The  Composition  of  Sea-water. 
— Presence  of  Organic  Matter. — Analysis  of  the  contained  Gases. — Differ- 
ences of  Specific  Gravity. — Conclusion    Page  467 

Appendix  A. — Summary  of  the  Results  of  the  Examination  of  Samples  of 
Sea-water  taken  at  the  Surface  and  at  various  Depths,  By  William  Lant 
Carpenter,  B.A.,  B.Sc Page  502 

Appendix  B. — Results  of  the  Analyses  of  Eight  Samples  of  Sea-water 
collected  during  the  Third  Cruise  of  the  '  Porcupine.'  By  Dr.  Frank- 
land,  F.R.S Page  511 

Appendix  C. — Notes  on  Specimens  of  the  Bottom  collected  during  the  First 
Cruise  of  the  '  Porcupine '  in  1869.     By  David  Forbes,  F.R.S.    Page  514 

Appendix  D. — Note  on  the  Carbonic  Acid  contained  in  Sea-water.  By 
John  Young  Buchanan,  M.A.,  Chemist  to  the  'Challenger'  Expedition. 

Page  518 

INDEX     Page  523 


LIST  OF   ILLUSTllATIONS, 


WOODCUTS. 

FIO.  PACK 

1.  AsTEROPHYTON  LiNCKii,  Miiller  and  Troschel.     A  young  speci- 

men slightly  enlarged  (No.  75) 

2.  Globigerina  bulloides,  D'Orbigny.     Highly  magnified  . . . 

3.  Orbulina  universa,  D'Orbigny.     Highly  magnified  

4.  Caryophyllia    borealis,   Fleming.      Twice   the   natural  size 

(No.  45)        - 

5.  Brisinga  coronata,  G.  0.  Sars,     Natural  size.     (No.  7) 

6.  HoLTENiA  CARPENTERi  (sp.  n.).     Half  the  natural  size.     (No.  12] 

7.  TisiPHONiA  AGARiciFORMis  (sp.  n.).     Natural  size.     (No.  12)    .. 

8.  GoNOPLAX  RHOMBOiDES,  Fabricius.     Young.     Twice  tlie  natural 

size.     (No.  3)      

9.  Geryon    TRiDENS,  Kroyer.     Young.      Twice  the    natural   size 

(No.  7) 

10.  Orbitolites   tenuissimus,  Carpenter  MSS.     Magnified.     (No 

28)         

11.  PoROCiDARis  PURPURATA  (sp.  n.).     Natural  size.     (No.  47)     .. 

12.  Pourtalesia  jeffreysi  (sp.  n.).     Slightly  enlarged.     (No.  64)     108 

13.  Stylocordyla  borealis,  Loven  (sp.).      Natural  size.     (No.  64)     114 

14.  SoLASTER    FURCiFER,  VoH  Dubeu  and   Koren.      Natural  size. 

(No.  55)        119 

15.  KoRETHRASTER    HispiDUS  (sp.  H.).      Dorsal  aspect.     Twice  the 

natural  size.     (No.  57) 119 

16.  Hymenaster  pellucidus   (sp.  n.).     Ventral  aspect.     Natural 

size.     (No.  59)     120 

17.  Arch  aster   bifrons  (sp.  n.).     Dorsal  aspect.     Three-fourths  of 

the  natural  size.    (No.  57) 122 

18.  EusiRUS  CUSPID ATUS,  Kroyer.     (No.  55) 125 

19.  Caprella    spinosissima,    Norman.      Twice    the    natural  size. 

(No.  59)       12(J 

b 


88 


91 
102 


XVlll 


LIST  OF  ILLUSTRATIONS. 


20. 
21. 

22. 
23. 

24. 

25. 

26. 

27. 

'28. 

29. 

30. 

31. 
32. 

33. 
34. 

35. 

36. 

37. 
38. 
39. 

40. 
41. 
42. 
43. 
44. 
45. 
46. 


^3A  NASUTA,  Norman.    Slightly  enlarged.     (No.  55)       

Arctorus    baffini,  Sabine.      About   the   natural   size.     (No. 

59)        ...     •    

Nymphon  abyssorum,  Norman.  Slightly  enlarged.  (No.  56) 
Thecophora  semisuberites,  Oscar  Schmidt.    Twice  the  natural 

size.     (No.  76)    

Thecophora  ibla  (sp.  n.).  Twice  the  natural  size.  (No.  76) 
Archaster   vexillifer  (sp.  n.).      One-third  the  natural  size. 

(No.  76)       

Zoroaster  fulgens  (sp.  n.).     One-third  the  natural  size.     (No. 

78)       - 

Calveria  hystrix  (sp.  n.).    Two-thirds  the  natural  size.     (No. 

86)         ... 

Calveria  hystrix  (sp.  n.).    Inner  surface  of  a  portion  of  the 

test  showing  the  structure  of  the  ambulacral  and  iuterambu- 

lacral  areas  ... 

Calveria   fenestrata  (sp.  n.).    One  of  the  four-valved  pedi- 

cellarite        ...     

Lophohelia  prolifera,  Pallas  (sp.).    Three-fourths  the  natural 

size.     (No.  26)     

Allopora  oculina,  Ehrenberg      

Ophiomusium  lymani   (sp.  n.).     Dorsal  surface.    Natural  size. 

(No.  45)       

Ophiomusium  lymani  (sp.  n.).     Oral  surface      

Uorynchus  thomsoni,  Norman.     Once  and  a  half  the  natural 

size  ;  everywhere  in  deep  water        

Amathia  carpenteri,  Norman.     Once  and  a  half  the  natural 

size.     (No.  47)     

Chrondrocladia  virgata  (sp.  n.).      One-half  the  natural  size. 

(No.  33,P1.  V.) 

The  *  Cup-lead  '       


Brooke's  Deep-Sea  Sounding  Apparatus 


• I 


The 'Bull-Dog'  Sounding  Machine        

The  '  Fitzgerald  '  Sounding  Machine     

The 'Hydra'  Sounding  Machine      

'Massey's'  Sounding  Machine 

Otho  Frederick  Muller's  Dredge,     a.d.  1750     

'Ball's  Dredge'     

The  Stern  Derrick  of  the  '  Porcupine,'  showing  the 
'  Accumulator,'  the  Dredge,  and  the  Mode  of  stowing 
the  Rope    

The  End  of  the  Dredge-frame        


PAGB 

127 

128 
129 

147 
148 

150 

153 

156 

157 

159 

169 
170 

172 
173 

174 

175 

187 
210 
211 
213 
215 
217 
218 
225 
239 
240 


248 
250 


LIST  OF  ILLUSTRATIONS.  xix 

*'">•  PAGK 

48.  dlledqe-fkame,  showing  the  mode  of  attachment  of  the 

Bag       251 

49.  The   End   of   the   Dredge-frame,  showing  the  Mode  of 

Attachment  of  the  Bag       252 

50.  Diagram   of   the   relative  Position    of  the  Vessel,  the 

Weights,  and  the  Dredge,  in  dredging  in  Deep  Water  253 

51.  Dredge  with  'Hempen  Tangles'      257 

52.  Set  of  Dredging  Sieves 260 

53.  The  Miller-Oasella  Modification  of  Six's  Self- register- 

ing Thermometer     291 

54.  Copper   Case  for  protecting    the   Miller-Casella  Ther- 

mometer        292 

55.  Serial  Sounding,  Station  64       312 

56.  Serial  Sounding,  Station  87        312 

57.  Curves  constructed  from  Serial  Soundings  in  the  'Warm'- 

AND  *  Cold-Areas'  in  the  Channel  between  Scotland 
AND  FiiROE         315 

58.  Curves  constructed  from  Serial  and  Bottom  Soundings  in 

the  Channel  between  Scotland  and  Rockall    319 

59.  Diagram  representing  the  Relation  between  Depth  and 

Temperature  off  Rockall 322 

60.  Diagram  representing  the  Relation  between  Depth  and 

Temperature  in  the  Atlantic  Basin      322 

61.  Curves  constructed  from  Serial  and  Bottom  Temperature 

Soundings  IN  THE  Atlantic  Basin      324 

62.  Diagram  representing  the  Relation  between  Depth  and 

Temperature,    from    the    Temperature    Observations 

TAKEN  between   CaPE   FiNISTERRE  AND  CaPE  St.  ViNCENT, 

August  1870      327 

<)3.     "Eine  grossere  Cytode  von  Bathibius  mit  EINGEBETTETEN 

COCCOLITHEN "  (x.  700) 412 

64.  '  CoccosPHERE '  (x.  1000)         414 

65.  RossELLA  VELATA  (sp.  n.).     Natural  size.     (No.  32,  1870)        ...     419 

66.  Hyalonema  lusitanicum,  Barboza  du  Bocage.   Half  the  natural 

size.     (No.  90,  1869) 421 

67.  AsKONEMA  setubalense,  Kent.     One-eighth  the  natural  size. 

(No.  25,  1870)      ...     429 

68.  Flabellum  distinctum.   Twice  the  natural  size.    (No.  28,  1870)     432 

69.  Thecopsammia  socialis,  Pourtales.    Once  and  a  half  the  natural 

size.     (No.  57,  1869) 433 

70.  Pentacrinus  asteria,  Linnaeus.     One-fourth  the  natural  size  ...    436 

71.  Pentacrinus  wyville-thomsoni,  JeflFreys.     Natural  size,     (No, 

17,1870)      443 


XX 


LIST  OF  ILLUSTRATIONS. 


FIG. 

73. 

74. 


77. 
78. 

71). 

80. 

81. 

82. 
83. 
84. 


PAGE 

Rhizocrinus  loffotensis,  M.  Sars.    Ouce  aud  a  half  the  natural 

size.     (No.  43,  1869) 451 

Bathycrinus  gracilis  (sp.  n.).     Twice  the  natural  size.     (No. 

37,1869)       ...     453 

Archaster   bifrons  (sp.  n.).      Oral  aspect.     Three-fourths  the 

natural  size.     (No.  57,  1869)     455 

SoLASTER    furcifer,   Vou    Dubcn  and  Koren.      Oral    aspect. 

Natural  size.     (No.  55,  1869)    456 

BucciNOPSis  STRIATA,  Jeffreys.     Fseroe  Channel 464 

Latirus    albus,   Jetfreys.      Twice    the    natural    size.      Fseroe 

Channel 464 

Pleuronectia    lucida,  JeflFreys.      Twice  the  natural  size,     a, 

from  the  Eastern  Atlantic  ;  &,  from  the  Gulf  of  Mexico       ...     465 

Pecten  HOSKYNSi,  Forbes.     Twice  the  natural  size     465 

Ventriculites  simplex,  Toulmin  Smith.     Once  and  a  half  the 

natural  size 483 

Ventriculites  simplex,  Toulmin  Smith.     Outer  surface  ;   four 

times  the  natural  size 484 

Ventriculites  simplex,  Toulmin  Smith.     Section  of  the  outer 

wall,  showing  the  structure  of  the  silicious  network  (x.  50)  485 
CcELOsPH^RA    tubifex    (sp.  u.).     Slightly  enlarged.     Off  the 

Coast  of  Portugal        485 

'  Choanites.'     In  a  flint  from  the  white  chalk      486 


VIGNETTES. 


The  FyEROE  Islands xii 

TlNDHOLM 48 

Thorshavn          80 

The  Governor's  House,  Thorshavn 132 

Lille  Dimon      196 

NOLSO,    FROM    THE    HiLLS   ABOVE    ThORSHAVN         ...  235 

FUGLO,    FROM   THE   EASTERN    ShORE    OF   ViDERO 280 

Vaay  Church  in  Sudero       .'    ...  328 

The  Giant  and  the  Hag      ...  406 

BORDO,   KUNO,   AND    KaLSO,    FROM    THE    HaMLET    OF   ViDERO 466 

KuNo,  FROM  Vaay  in  Bordo        501 


MAPS   AND    PLATES. 


To  face 
page 

.       59 

1869      

.      87 

—1869 

.       95 

-1869      

.     106 



.     180 

PLATE 

I.— Track  of  H.M.S.  *  Lightning '—1868 
II. — First  Cruise  of  H.M.S.  '  Porcupine '- 
III. — Second  Cruise  of  H.M.S.  'Porcupine 
IV. — Third  Cruise  of  H.M.S.  'Porcupine '- 
v.— Track  of  H.M.S.  '  Porcupine '—1870 
VI. — Diagram  of  the    'Porcupine'  Soundings  in  the  Atlan- 
tic and  in  the  F^roe  Channel,  showing  the  Eelation 
between  Temperature  and  Depth, — the  Serial  Sound- 
ings  REDUCED   to   CuRVES.      ThE  NUMBERS  REFER  TO   THE 

Stations  on  the  Charts,  Plates  II.,  III.,  and  IV.   ... 

VII. — Physical  Chart  of  the  North  Atlantic  :  showing  the 
Depth,  and  the  General  Distribution  of  Temperatures 
for  the  Month  of  July     

VIII. — Map  showing  the  General  Distribution  of  the  Ter- 
tiary, the  Cretaceous,  and  the  Jurassic  Systems 
IN  the  North- West  of  Europe  with  reference  to 
Contour    


323 


363 


474 


THE 


DEPTHS   OF   THE   SEA. 


THE  DEPTHS  OF  THE  SEA, 


C  H  A  P  T  E  11     I. 

INTRODUCTION. 

The  Question  of  a  Batliymetrical  Limit  to  Life. — The  general  Laws 
which  regulate  the  Geographical  Distribution  of  Living  Beings. — 
Professor  Edward  Forbes'  Investigations  and  Views. — Specific 
Centres. — Eepresentative  Species. — Zoological  Provinces. — Bear- 
ings of  a  Doctrine  of  Evolution  upon  the  Idea  of  a  '  Species/ 
and  of  the  Laws  of  Distribution. — The  Circumstances  most  likely 
to  affect  Life  at  great  Depths  :  Pressure,  Temperature,  and  Absence 
of  Light. 

The  sea  covers  nearly  three-fourths  of  the  surface  of 
the  earth,  and,  until  within  the  last  few  years,  very 
little  was  known  with  anything  like  certainty  about 
its  depths,  whether  in  their  physical  or  their  biological 
relations.  The  popular  notion  was,  that  after  arriving 
at  a  certain  depth  the  conditions  became  so  peculiar, 
so  entirely  different  from  those  of  any  portion  of  the 
earth  to  which  we  have  access,  as  to  preclude  any 
other  idea  than  that  of  a  waste  of  utter  darkness,  sub- 
jected to  such,  stupendous  pressure  as  to  make  life  of 
any  kind  impossible,  and  to  throw  insuperable  diffi- 
T  B 

t 


2  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

culties  in  the  way  of  any  attempt  at  investigation. 
Even  men  of  science  seemed  to  share  this  idea,  for 
they  gave  little  heed  to  the  apparently  well-authenti- 
cated instances  of  animals,  comparatively  high  in  the 
scale  of  life,  having  been  brought  up  on  sounding 
lines  from  great  depths,  and  welcomed  any  suggestion 
of  the  animals  having  got  entangled  when  swimming 
on  the  surface,  or  of  carelessness  on  the  part  of  the 
observers.  And  this  was  strange,  for  every  other 
question  in  Physical  Geography  had  been  investi- 
gated by  scientific  men  Avith  consummate  patience 
and  energy.  Every  gap  in  the  noble  little  army  of 
martyrs  striving  to  extend  the  boundaries  of  know- 
ledge in  the  wilds  of  Australia,  on  the  Zambesi, 
or  towards  the  North  or  South  Pole,  was  struggled 
for  by  earnest  volunteers,  and  still  the  great  ocean 
slumbering  beneath  the  moon  covered  a  region 
apparently  as  inaccessible  to  man  as  the  '  mare 
serenitatis/ 

A  few  years  ago  the  bottom  of  the  sea  was  required 
for  the  purpose  of  telegraphic  communication,  and 
practical  men  mapped  out  the  bed  of  the  North 
Atlantic,  and  devised  ingenious  methods  of  ascertain- 
ing the  nature  of  the  material  covering  the  bottom. 
They  laid  a  telegraphic  cable  across  it,  and  the  cable 
got  broken  and  they  went  back  to  the  spot  and  fished 
up  the  end  of  it  easily,  from  a  depth  of  nearly  two 
miles. 

It  had  long  been  a  question  with  naturalists  whether 
it  might  not  be  possible  to  dredge  the  bottom  of  the 
sea  in  the  ordinary  way,  and  to  send  down  water- 
bottles  and  registering  instruments  to  settle  finally 
the  question  of  a  '  zero  of  animal  life,'  and  to  deter- 


CHAP.  1.]  INTRODUCTION.  3 

mine  with  precision  the  composition  and  temperature 
of  sea-water  at  great  depths.  An  investigation  of  this 
kind  is  beyond  the  ordinary  limits  of  private  enter- 
prise. It  requires  more  power  and  sea  skill  than 
naturalists  can  usually  command.  "When,  however, 
in  the  year  1868,  at  the  instance  of  my  colleague 
Dr.  Carpenter  and  myself,  with  the  effective  support 
of  the  present  Hydrographer  to  the  Navy,  w^ho  is 
deeply  interested  in  the  scientific  aspects  of  his  pro- 
fession, w^e  had  placed  at  our  disposal  by  the  Admi- 
ralty sufiicient  power  and  skill  to  make  the  experiment, 
we  found  that  we  could  work,  not  with  so  much  ease, 
but  with  as  much  certainty,  at  a  depth  of  600  fathoms 
as  at  100  ;  and  in  1869  we  carried  the  operations  down 
to  2,435  fathoms,  14,610  feet,  nearly  three  statute 
miles,  with  perfect  success. 

Dredging  in  such  deep  water  was  doubtless  very 
trying,  Each  haul  occupied  seven  or  eight  hours  ; 
and  during  the  whole  of  that  time  it  demanded  and 
received  the  most  anxious  care  on  the  part  of  our 
commander,  who  stood  with  his  hand  on  the  pulse  of 
the  accumulator  ready  at  any  moment,  by  a  turn  of 
the  paddles,  to  ease  any  undue  strain.  The  men, 
stimulated  and  encouraged  by  the  cordial  interest 
taken  by  their  officers  in  our  operations,  worked 
willingly  and  well ;  but  the  labour  of  taking  upw^ards 
of  three  miles  of  rope  coming  up  with  a  heavy  strain, 
from  the  surging  drum  of  the  engine,  was  very  severe. 
The  rope  itself,  'hawser-laid,'  of  the  best  Italian 
hemp,  2\  inches  in  circumference,  with  a  breaking 
strain  of  2\  tons,  looked  frayed  out  and  worn,  as  if  it 
could  not  have  been  trusted  to  stand  this  extraordinary 
ordeal  much  longer. 

B  2 


4  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

Still  the  thing  is  possible,  and  it  must  be  done 
again  and  again,  as  the  years  pass  on,  by  naturalists  of 
all  nations,  working  with  improving  machinery,  and 
with  ever-increasing  knowledge.  Por  the  bed  of  the 
deep  sea,  the  140,000,000  of  square  miles  which  we 
have  now  added  to  the  legitimate  field  of  Natural 
History  research,  is  not  a  barren  waste.  It  is  inhabited 
by  a  fauna  more  rich  and  varied  on  account  of  the 
enormous  extent  of  the  area,  and  with  the  organisms 
in  many  cases  apparently  even  more  elaborately  and 
delicately  formed,  and  more  exquisitely  beautiful  in 
their  soft  shades  of  colouring  and  in  the  rainbow-tints 
of  their  wonderful  phosphorescence,  than  the  fauna 
of  the  well-known  belt  of  shallow  water  teeming  with 
innumerable  invertebrate  forms  which  fringes  the 
land.  And  the  forms  of  these  hitherto  unknown 
living  beings,  and  their  mode  of  life,  and  their  rela- 
tions to  other  organisms  whether  living  or  extinct, 
and  the  phenomena  and  laws  of  their  geographical 
distribution,  must  be  worked  out. 

The  late  Professor  Edward  Porbes  appears  to  have 
been  the  first  wlio  undertook  the  systematic  study  of 
Marine  Zoology  with  special  reference  to  the  distribu- 
tion of  marine  animals  in  space  and  in  time.  After 
making  himself  well  acquainted  with  the  fauna  of 
the  British  seas  to  the  depth  of  about  200  fathoms  by 
dredging,  and  by  enlisting  the  active  co-operation  of 
his  friends — among  whom  we  find  MacAndrew,  Barlee, 
Gwyn  Jeff'reys,  William  Thompson,  Eobert  Ball,  and 
many  others,  entering  enthusiastically  into  the  new 
field  of  Natural  History  inquiry — in  the  year  1841 
Porbes  joined  Capt.  Graves,  Avho  was  at  that  time  in 
command  of  the  Mediterranean  Survey,  as  naturalist. 


CHAP.  I.]  INTRODUCTION.  5 

During  about  eighteen  months  he  studied  with  the 
utmost  care  the  conditions  of  the  ^gean  and  its 
shores,  and  conducted  upwards  of  one  hundred 
dredging  operations  at  depths  varying  from  1  to  130 
fathoms.  In  1843  he  communicated  to  the  Cork 
meeting  of  the  British  Association  an  elaborate  report 
on  the  Mollusca  and  Radiata  of  the  jEgean  Sea,  and 
on  their  distribution  considered  as  bearing  on  Geology.^ 
Three  years  later,  in  1846,  he  published  in  the  first 
volume  of  the  '  Memoirs  of  the  Geological  Survey  of 
Great  Britain,'  a  most  valuable  memoir  upon  the. 
Connection  between  the  existing  Eauna  and  Elora  of 
the  British  Isles,  and  the  geological  Changes  which 
have  affected  their  Area,  especially  during  the  Epoch 
of  the  Northern  Drift.^  In  the  year  1859  appeared 
the  Natural  History  of  the  European.  Seas  by  the  late 
Professor  Edward  Eorbes,  edited  and  continued  by 
Bobert  Godwin  Austen.^  In  the  first  hundred  pages 
of  this  little  book,  Eorbes  gives  a  general  outline  of 
some  of  the  more  important  of  his  views  with  regard 

^  Eeport  on  the  Mollusca  and  Kadiata  of  the  ^gean  Sea,  and  on 
their  Distribution,  considered  as  bearing  on  Geology.     By  Edward 
Forbes,  F.L.S.,  M.W.S.,  Professor  of  Botany  in  King's  College,  London.  • 
(Report  of  the  Thirteenth  Meeting  of  the  British  Association  for  the  Ad- 
vancement of  Science  ;  held  at  Cork  in  August  1843.    London,  1844.) 

2  On  the  Connection  between  the  Distribution  of  the  existing  Fauna 
and  Flora  of  the  British  Isles  and  the  geological  Changes  which  have 
affected  their  Area,  especially  during  the  Epoch  of  the  Northern  Drift. 
By  Edward  Forbes,  F.R.S.,  L.S.,  G.S.,  Professor  of  Botany  at  King's 
College,  London ;  Palaeontologist  to  the  Geological  Survey  of  the 
United  Kingdom.  (Memoirs  of  the  Geological  Survey  of  Great  Britain, 
vol.  i.     London,  1846.) 

2  The  Natural  History  of  the  European  Seas,  by  the  late  Professor 
Edward  Forbes,  F.R.S.,  &c.  Edited  and  continued  by  Robert  Godwin 
Austen,  F.R.S.     London,  1859. 


6  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

to  the  distribution  of  marine  forms.  The  remainder 
of  the  book  is  a  continuation  by  his  friend  Mr.  Godwin 
Austen,  for  before  it  was  finished  an  early  death  had 
cut  short  the  career  of  the  most  accomplished  and 
original  naturalist  of  his  time. 

I  will  give  a  brief  sketch  of  the  general  results  to 
which  Forbes  was  led  by  his  labours,  and  I  shall 
have  to  point  out  hereafter,  that  although  we  are 
now  inclined  to  look  somewhat  differently  on  certain 
very  fundamental  points,  and  although  recent  inves- 
tigations w^ith  better  appliances  and  more  extended 
experience  have  invalidated  many  of  his  conclusions, 
to  Eorbes  is  due  the  credit  of  having  been  the  first  to 
treat  these  questions  in  a  broad  philosophical  sense, 
and  to  point  out  that  the  only  means  of  acquiring  a 
true  knowledge  of  the  rationale  of  the  distribution  of 
our  present  fauna,  is  to  make  ourselves  acquainted 
with  its  history,  to  connect  the  present  with  the  past. 
This  is  the  direction  which  must  be  taken  by  future 
inquiry.  Eorbes,  as  a  pioneer  in  this  line  of  research, 
was  scarcely  in  a  position  to  appreciate  the  full  value 
of  his  work.  Every  year  adds  enormously  to  our 
stock  of  data,  and  every  new  fact  indicates  more 
clearly  the  brilliant  results  which  are  to  be  obtained 
by  following  his  methods,  and  by  emulating  his 
enthusiasm  and  his  indefatigable  industry. 

Porbes  believed  implicitly,  along  with  nearly  all  the 
leading  naturalists  of  his  time,  in  the  immutability 
of  species.  He  says  (Natural  History  of  the  British 
Seas,  p.  8),  "Every  true  species  presents  in  its  indi- 
viduals, certain  features,  specific  characters,  which 
distinguish  it  from  every  other  species ;  as  if  the 
Creator  had  set  an  exclusive  mark  or  seal  on  each 


CHAP.  I.]  INTRODUCTION.  7 

type."  He  likewise  believed  in  specific  centres  of 
distribution.  He  held  that  all  the  individuals  com- 
posing a  species  had  descended  from  a  single  pro- 
genitor, or  from  two,  according  as  the  sexes  might  be 
united  or  distinct,  and  that  consequently  the  idea  of  a 
species  involved  the  idea  of  the  relationship  in  all  the 
individuals  of  common  descent;  and  the  converse,  that 
there  could  by  no  possibility  be  community  of  descent 
except  in  living  beings  which  possessed  the  same 
specific  characters.  He  supposed  that  the  original 
individual  or  pair  was  created  at  a  particular  spot 
where  the  conditions  were  suitable  for  its  existence 
and  propagation,  and  that  the  species  extended  and 
migrated  from  that  spot  on  all  sides  over  an  area  of 
greater  or  less  extent,  until  it  met  with  some  natural 
barrier  in  the  shape  of  unsuitable  conditions.  No 
specific  form  could  have  more  than  a  single  centre  of 
distribution.  If  its  area  appeared  to  be  broken  up,  a 
patch  not  in  connection  with  the  original  centre  of 
distribution  occurring  in  some  distant  locality,  it  was 
accounted  for  by  the  formation,  through  some  geolo- 
gical change  after  the  first  spread  of  the  species,  of  a 
barrier  which  cut  off  a  part  of  its  area;  or  to  some 
accidental  transport  to  a  place  where  the  conditions 
were  sufficiently  similar  to  those  of  its  natural  original 
habitat  to  enable  it  to  become  naturalized.  No  species 
once  exterminated  was  ever  recreated,  so  that  in  those 
few  cases  in  which  we  find  a  species  abundant  at  one 
period  over  an  area,  absent  over  the  same  area  for  a 
time,  and  recurring  at  a  later  period,  it  must  be  ac- 
counted for  by  a  change  in  the  conditions  of  the  area 
which  forced  the  emigration  of  the  species,  and  a  sub- 
sequent further  change  which  permitted  its  return. 


8  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

Porbes  defined  and  advocated  what  he  called  the 
law  of  representation.  He  found  that  in  all  parts 
of  the  world,  however  far  removed,  and  however 
completely  separated  by  natural  barriers,  where  the 
conditions  of  life  are  similar,  species  and  groups 
of  species  occur  which,  although  not  identical, 
resemble  one  another  very  closely;  and  he  found 
that  this  similarity  existed  likewise  between  -  groups 
of  fossil  remains,  and  between  groups  of  fossils 
and  groups  of  recent  forms.  Admitting  the  con- 
stancy of  specific  characters,  these  resemblances 
could  not  be  accounted  for  by  commimity  of  de- 
scent, and  he  thus  arrived  at  the  generalization, 
that  in  localities  placed  under  similar  circumstances, 
similar  though  specifically  distinct  specific  forms 
were  created.  These  be  regarded  as  mutually  repre- 
sentative species. 

Our  acceptance  of  the  doctrines  of  specific  centres 
and  of  representation,  or,  at  all  events,  the  form  in 
which  we  may  be  inclined  to  accept  these,  depends 
greatly  upon  the  acceptance  or  rejection  of  the  funda- 
mental dogma  of  the  immutability  of  species ;  and 
on  this  point  there  has  been  a  very  great  change  of 
opinion  within  the  last  ten  or  twelve  years,  a  change 
certainly  due  to  the  remarkable  ability  and  candour 
with  which  the  question  has  been  discussed  by  Mr. 
Darwin^  and  Mr.  Wallace,^  and  to  the  genius  of  Pro- 

^  The  Origin  of  Species  by  means  of  Natural  Selection ;  or,  the 
Preservation  of  Favoured  Eaces  in  the  Struggle  for  Life.  By  Charles 
Darwin,  M.A.,  F.E.S.,  L.S.,  G.S.,  &c.  &c.  London,  1859,  and  subse- 
quent editions. 

2  Contributions  to  the  Theory  of  Natural  Selection.  A  Series  of 
Essays  by  Alfred  Eussel  Wallace.     London,  1870. 


CHAP.  1.]  INTRODUCTION.  9 

fessor  Ernst  Haeckel/  Dr.  Fritz  Miiller,^  and  others  of 
their  enthusiastic  disciples  and  commentators.  I  do 
not  think  that  I  am  speaking  too  strongly  when  I  say- 
that  there  is  now  scarcely  a  single  competent  general 
naturalist  who  is  not  prepared  to  accept  some  form 
of  the  doctrine  of  evolution. 

There  is,  no  douht,  very  great  difficulty  in  the 
minds  of  many  of  us  in  conceiving  that,  commenc- 
ing from  the  simplest  living  being,  the  present  state 
of  things  in  the  organic  world  has  been  produced 
solely  by  the  combined  action  of  '  atavism/  the  ten- 
dency of  offspring  to  resemble  their  parents  closely ; 
and  'variation,'  the  tendency  of  offspring  to  differ 
individually  from  their  parents  within  very  narrow 
limits  :  and  many  are  inclined  to  believe  that  some 
other  law  than  the  '  survival  of  the  fittest '  must 
regulate  the  existing  marvellous  system  of  extreme 
and  yet  harmonious  modification.  Still  it  must  be 
admitted  that  variation  is  a  vera  causa,  capable, 
within  a  limited  period,  under  favourable  circum- 
stances, of  converting  one  species  into  what,  accord- 
ing to  our  present  ideas,  we  should  be  forced  to 
recognize  as  a  different  species.  And  such  being  the 
case,  it  is,  perhaps,  conceivable  that  during  the  lapse 
of  a  period  of  time — still  infinitely  shorter  than 
eternity — variation  may  have  produced  the  entire 
result. 

^  Generelle  Morphologie  der  Organismen.  AUgemeine  Grundziige 
der  organischen  Formen-Wissenscliaft  mechanisch  begriindet  durch 
die  von  Charles  Darwin  reformirte  Descendenz-Theorie.  Yon  Ernst 
Haeckel.  Berlin,  1866. — ]N"atiirliclie  Sclibpfungsgescliiclite.  Yon  Dr. 
Ernst  Haeckel,  Professor  an  der  TJniversitat  Jena.     Berlin,  1870. 

2  FUr  Darwin.  Yon  Dr.  Fritz  Miiller.  Leipzig,  1864.  Translated 
from  the  German  by  W.  S.  Dallas,  F.L.S.     London,  1869. 


]  0  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

The  individuals  comprising  a  species  have  a  definite 
range  of  variation  strictly  limited  by  the  circum- 
stances under  which  the  group  of  individuals  is 
placed.  Except  in  man,  and  in  domesticated  animals 
in  which  it  is  artificially  increased,  this  individual 
variation  is  usually  so  slight  as  to  be  unappreciable 
except  to  a  practised  eye ;  but  any  extreme  variation 
which  passes  the  natural  limit  in  any  direction 
clashes  in  some  way  with  surrounding  circum- 
stances, and  is  dangerous  to  the  life  of  the  indivi- 
dual. The  normal  or  graphic  line,  or  '  line  of 
safety,'  of  the  species,  lies  midway  between  the 
extremes  of  variation. 

If  at  any  period  in  the  history  of  a  species  the 
conditions  of  life  of  a  group  of  individuals  of  the 
species  be  gradually  altered,  with  the  gradual  change 
of  circumstances  the  limit  of  variation  is  contracted 
in  one  direction  and  relaxed  in  another ;  it  becomes 
more  dangerous  to  diverge  towards  one  side  and 
more  desirable  to  diverge  towards  the  other,  and  the 
position  of  the  lines  limiting  variation  is  altered. 
The  normal  line,  the  line  along  which  the  specific 
characters  are  most  strongly  marked,  is  consequently 
slightly  deflected,  some  characters  being  more  strongly 
expressed  at  the  expense  of  others.  This  deflection,  car- 
ried on  for  ages  in  the  same  direction,  must  eventually 
carry  the  divergence  of  the  varying  race  far  beyond 
any  limit  within  which  we  are  in  the  habit  of 
admitting  identity  of  species. 

But  the  process  must  be  infinitely  slow.  It  is  diffi- 
cult to  form  any  idea  of  ten,  fifty,  or  a  hundred  mil- 
lions of  years ;  or  of  the  relation  which  such  periods 
bear  to  changes  taking  place  in  the  organic  world. 


CHAP.  I.]  INTRODUCTION.  1 1 

We  must  remember,  however,  that  the  rocks  of 
the  Silurian  system,  overlaid  by  ten  miles'  thickness 
of  sediment  entombing  a  hundred  successive  faunae, 
each  as  rich  and  varied  as  the  fauna  of  the  present 
day,  themselves  teem  with  fossils  fully  representing 
all  the  existing  classes  of  animals,  except  perhaps 
the  highest. 

If  it  be  possible  to  imagine  that  this  marvellous 
manifestation  of  Eternal  Power  and  Wisdom  involved 
in  living  nature  can  have  been  worked  out  through 
the  law  of  '  descent  with  modification '  alone,  we 
shall  certainly  require  from  the  Physicists  the  longest 
row  of  cyphers  which  they  can  afford. 

Now,  although  the  admission  of  a  doctrine  of  evolu- 
tion must  affect  greatly  our  conception  of  the  origin 
and  rationale  of  so-called  specific  centres,  it  does  not 
practically  affect  the  question  of  their  existence,  or  of 
the  laws  regulating  the  distribution  of  species  from 
their  centres  by  migration,  by  transport,  by  ocean 
currents,  by  elevations  or  depressions  of  the  land,  or 
by  any  other  causes  at  work  under  existing  circum- 
stances. So  far  as  practical  naturalists  are  con- 
cerned, species  are  permanent  within  their  narrow 
limits  of  variation,  and  it  would  introduce  an  element 
of  infinite  confusion  and  error  if  we  were  to  regard 
them  in  any  other  light.  The  origin  of  species  by 
descent  with  modification  is  as  yet  only  a  hypothesis. 
During  the  whole  period  of  recorded  human  observa- 
tion not  one  single  instance  of  the  change  of  one 
species  into  another  has  been  detected ;  and,  singular 
to  say,  in  successive  geological  formations,  although 
new  species  are  constantly  appearing  and  there  is 
abundant  evidence  of  progressive  change,  no  single  case 


1 2  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

has  yet  been  observed  of  one  species  passing  through 
a  series  of  inappreciable  modifications  into  another. 
Every  species  appears  to  have  an  area  of  maximum 
development,  and  this  has  been  called  the  metropolis 
of  the  species ;  and  practically  we  must  employ  the 
same  methods  in  investigating  the  laws  of  its  distri- 
bution as  if  we  still  regarded  it  as  having  been 
specially  created  in  its  metropolis. 

It  is  the  same  in  dealing  with  the  law  of  represen- 
tation. Accepting  an  evolution  doctrine,  we  should 
certainly  regard  closely  allied  or  '  representative ' 
species  as  having  descended  comparatively  recently 
from  a  common  ancestry,  and  as  having  diverged 
from  one  another  under  somewhat  different  conditions 
of  life.  It  is  possible  that  as  our  knowledge  increases 
we  may  be  able  to  trace  the  pedigree  of  our  modern 
species,  and  some  attempts  have  already  been  made 
to  sketch  out  the  main  branches  of  the  universal 
genealogical  tree;^  but  practically  we  must  continue 
to  accord  a  specific  rank  to  forms  which  exhibit 
characters  to  which  we  have  been  in  the  habit  of 
assigning  specific  value. 

"Every  species  has  three  maxima  of  develop- 
ment,— in  depth,  in  geographic  space,  in  time.  In 
depth,  we  find  a  species  at  first  represented  by  few 
individuals,  which  become  more  and  more  numerous 
until  they  reach  a  certain  point,  after  which  they 
again  gradually  diminish,  and  at  length  altogether 
disappear.  So  also  in  the  geographic  and  geologic 
distribution  of  animals.  Sometimes  the  genus  to 
which  the  species  belongs  ceases  with  its  disappear- 
ance, but  not  unfrequently  a  succession  of  similar 

^  Ernst  Haeckel,  op.  cit. 


I 


CHAP.  I.]  INTRODUCTION.  13 

species  are  kept  up,  representative  as  it  were  of  each 
other.  When  there  is  such  a  representation,  the 
minimum  of  one  species  usually  commences  before 
that  of  which  it  is  representative  has  attained  its 
correspondent  minimum.  Porms  of  representative 
species  are  similar,  often  only  to  be  distinguished  by 
critical  examination."  ^ 

As  an  illustration  of  what  is  meant  by  the  law  of 
'  representation,'  I  may  cite  a  very  curious  case  men- 
tioned by  Mr.  Verril  and  Mr.  Alexander  Agassiz.  On 
eitlier  side  of  the  Isthmus  of  Panama  the  Echinoderm 
order  EcMnidea,  the  sea-urchins,  are  abundant ;  but 
the  species  found  on  the  two  sides  of  the  Isthmus 
are  distinct,  although  they  belong  almost  universally 
to  the  same  genera,  and  in  most  cases  each  genus  is 
represented  by  species  on  each  side  which  resemble 
one  another  so  closely  in  habit  and  appearance  as  to 
be  at  first  sight  hardly  distinguishable.  I  arrange 
a  few  of  the  most  marked  of  these  from  the  Carib- 
bean and  Panamic  sides  of  the  Isthmus  in  parallel 
columns. 

Eastern  Fauna.  Western  Fauna. 

Cidaris  annulata,  Gray.  Cidaris  thouarsii,  Yal. 

Diadema  antillarum,  Phil.  Diadema  mexicanum,  A.  Ag. 

Ec/miocidaris  punctulatay  Desml.  Echinocidaris  stellata,  Ag. 

Echinometra  michelini,  Des.  Echinometra  van  hrunti,  A.  Ag. 

„  viridis,  A.  Ag.  „  rupicola,  A.  Ag. 

Lytechinus  variegatus,  A.  Ag.  Lytechinus  semituherculatus, 

A.  Ag. 

Trijmeustes  ventricosus,  Ag.  Tripneustes  depressus,  A.  Ag. 

Stolonoclypus  ravenellii,  A.  Ag.  Stolonoclypus  rotundus,  A.  Ag. 

Mellita  testudinata,  Kl.  Mellita  longifissa,  Mich. 

1  Edward  Forbes,  Eeport  on  ^gean  Invertebrata,  op.  cit.  p.  173. 


14  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

Eastern  Fauna.  Western  Fauna. 

Mdlita  hexapora^  A.  Ag.  Mellita  pacifica,  Ver. 

Encope  michelini,  Ag.  Encope  grandis,  Ag. 

„       emarginata,  Ag.  ,,       micropora,  Ag. 

Rhyncholampas  caribbcearmn,  Rhyncholampas  pacificus^  A.  Ag. 

A.  Ag. 

£riss2is  columharis,  Ag.  Brissus  obesus,  Yer. 

Meoma  ventricosa^  Lutk.  Meoma  grandis,  Gray. 

Plagionotus  pectoralis,  Ag.  Plagionotus  nobilis,  A.  Ag. 

Agassizia  excentrica,  A.  Ag.  Agassizia  scrobicidata,  Val. 

Moera  atropos,  Mich.  Moera  clotho,  Mich. 

Supposing  species  to  be  constant,  this  singular 
chain  of  resemblances  would  indicate  simply  the 
special  creation  on  the  two  sides  of  the  Isthmus  of 
two  groups  of  species  closely  resembling  one  another, 
because  the  circumstances  under  which  they  were 
placed  were  so  very  similar ;  but  admitting  '  descent 
with  modification/  while  gladly  availing  ourselves 
of  the  convenient  term  '  representation/  we  at  once 
come  to  the  conclusion  that  these  nearly  allied  '  re- 
presentative species '  must  have  descended  from  a  com- 
mon stock,  and  we  look  for  the  cause  of  their  diver- 
gence. Now  on  examining  the  Isthmus  of  Panama  we 
find  that  a  portion  of  it  consists  of  cretaceous  beds 
containing  fossils  un distinguishable  from  fossils  from 
the  cretaceous  beds  of  Europe ;  the  Isthmus  must 
therefore  have  been  raised  into  dry  land  in  tertiary  or 
post-tertiary  times.  It  is  difficult  to  doubt  that  the 
rising  of  this  natural  barrier  isolated  two  portions 
of  a  shallow-water  fauna  which  have  since  slightly 
diverged  under  slightly  different  conditions.  I  quote 
Alexander  Agassiz  : — "•  The  question  naturally  arises, 
have  we  not  in  the  different  Faunae  on  both  sides  of 
the  Isthmus  a  standard  by  which   to  measure  the 


1 


CHAP.  I.]  INTRODVCTION.  15 

changes  which  these  species  have  undergone  since  the 
raising  of  the  Isthmus  of  Panama  and  the  isolation 
of  the  two  Faunae?"' 

Edward  Porbes  distinguished  round  all  seaboards 
four  very  marked  zones  of  depth,  each  characterized 
by  a  distinct  group  of  organisms.  The  first  of  these 
is  the  littoral  zone,  the  space  between  tide-marks, 
distinguished  by  the  abundance  of  sea-weeds,  on 
the  European  shores  of  the  genera  Lichina,  Fucus, 
Enteromo7'pJia,  Folysiphonia,  and  Lmirencia,  which 
severally  predominate  at  different  heights  in  the 
zone,  and  subdivide  it  into  subordinate  belts  like 
a  softly-coloured  riband  border.  This  band  is  under 
very  special  circumstances,  for  its  inhabitants  are 
periodically  exposed  to  the  air,  to  the  direct  rays 
of  the  sun,  and  to  all  the  extremes  of  the  climate 
of  the  land.  Animal  species  are  not  very  numerous 
in  the  littoral  zone,  but  individuals  are  abundant. 
The  distribution  of  many  of  the  littoral  species  is 
very  wide,  and  some  of  them  are  nearly  cosmopolitan. 
Many  are  vegetable  feeders.  Some  characteristic 
genera  on  the  coast  of  Europe  are  Oammarus, 
Talitrus,  and  JBalanus  among  Crustacea,  and  Lit- 
torinct,  Patella,  Furpura,  and  Mytilus  among  Mol- 
lusca,  with,  under  stones  and  in  rock-pools,  many 
stragglers  from  the  next  zone. 

The  Laminarian  zone  extends  from  low-water  mark 
to  a  depth  of  about  fifteen  fathoms.    This  is  specially 

^  Preliminary  Report  on  the  Echini  and  Starfishes  dredged  in  Deep 
Water  between  Cuba  and  the  Florida  Pteef,  by  L.  F.  de  Pourtales, 
•  Assistant  U.S.  Coast  Survey;  prepared  by  Alexander  Agassiz. 
Communicated  by  Professor  B.  Peirce,  Superintendent  U.S.  Coast 
Survey,  to  the  Bulletin  of  the  Museum  of  Comparative  Zoology, 
Cambridge,  Mass.,  1869. 


16  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

the  zone  of  '  tangles  '  for  the  first  few  fathoms,  and 
in  deeper  water  of  the  beautiful  scarlet  sea-weeds 
(floridece).  It  is  always  under  water  except  at  the 
very  lowest  ebb  of  spring  tides,  when  we  get  a 
glimpse  of  its  upper  border.  Tiie  laminarian  zone 
produces  abundance  of  vegetable  food,  and,  like  the 
littoral  zone,  may  be  divided  into  subordinate  bands 
distinguished  by  differently  tinted  algae.  Animals 
swarm  in  this  zone,  both  as  to  species  and  indi- 
viduals, and  are  usually  remarkable  for  the  bright- 
ness of  their  colouring.  The  moUuscan  genera 
Trochus,  Lacuna,  and  Lottia  are  characteristic  of  this 
belt  in  the  British  seas. 

The  Laminarian  zone  is  succeeded  by  the  Coralline 
zone,  which  extends  to  a  depth  of  about  fifty  fathoms. 
In  this  belt  vegetation  is  chiefly  represented  by  coral- 
like millipores,  and  plant-like  hydroid  zoophytes  and 
bryozoa  abound.  All  of  the  higher  orders  of  marine 
invertebrates  are  fully  represented,  principally  by 
animal  feeders.  The  larger  crustaceans  and  echino- 
derms  are  abundant;  and  the  great  fishing-banks 
frequented  by  the  cod,  haddock,  halibut,  turbot,  and 
sole,  belong  properly  to  this  zone,  although  they 
sometimes  extend  into  water  more  than  fifty  fathoms 
deep.  Characteristic  moUuscan  genera  are  Buccinum, 
Fusus,  Ostrea,  and  Fecten;  and  among  echinoderms 
in  the  European  seas  we  find  Afitedon  sarsii  and 
celticus,  Astei^acanthion  glaciale  and  rubens,  Ophio- 
thrix  fragilis,  and  on  sand,  Ophioglypha  lacertosa 
and  alhida. 

The  last  belt  defined  by  Forbes  as  extending  from 
about  fifty  fathoms  to  an  unknown  lower  limit  is  the 
zone  of  deep-sea  corals.     '*  In  its  depths  the  number 


CHAP.  I.]  INTRODUCTION.  \J 

of  peculiar  creatures  are  few,  yet  sufficient  to  give  a 
marked  character  to  it,  whilst  the  other  portions  of  its 
population  are  derived  from  the  higher  zones,  and 
must  he  regarded  as  colonists.  As  we  descend  deeper 
and  deeper  in  this  region,  its  inhabitants  become  more 
and  more  modified,  and  fewer  and  fewer,  indicating 
our  approach  towards  an  abyss  where  life  is  either 
extinguished,  or  exhibits  but  a  few  sparks  to  mark 
its  lingering  presence.'" 

Eorbes  pointed  out  that  the  groups  of  animals  having 
their  maximum  development  in  these  several  zones 
are  thoroughly  characteristic,  and  that  groups  of 
representative  forms  occupy  the  same  zones  all  over 
the  world,  so  that  on  examining  an  assemblage  of 
marine  animals  from  any  locality,  it  is  easy  to  tell 
from  what  zone  of  depth  they  have  been  procured. 
At  all  periods  of  the  earth's  history,  there  has  been 
the  same  clear  definition  of  zones  of  depth,  and  fossil 
animals  from  any  particular  zone  are  in  some  sense 
representative  of  the  fauna  of  the  corresponding  zone 
at  the  present  day.  We  can,  therefore,  usually  tell 
with  tolerable  certainty  to  which  zone  of  depth  a  par- 
ticular assemblage  of  fossils  is  to  be  referred. 

Although  we  must  now  greatly  modify  our  views 
with  regard  to  the  extent  and  fauna  of  the  zone  of 
deep-sea  corals,  and  give  up  all  idea  of  a  zero  of 
animal  life,  still  we  must  regard  Forbes'  investiga- 
tion into  the  bathymetrical  distribution  of  animals 
as  marking  a  great  advance  on  previous  knowledge. 
His  experience  was  much  wider  than  that  of  any 
other  naturalist  of  his  time  ;  the  practical  difficulties 
in  the  way  of  testing  his  conclusions  were  great,  and 

*  Edward  Forbes,  Natural  History  of  the  European  Seas,  p.  26. 

C 


18  THE  DEPTHS  OF  THE  SEA.  [chap,  i, 


they  were  accepted  by  naturalists  generally  without 
question. 

The  history  of  discovery  bearing  upOn  the  extent  and 
distribution  of  the  deep-sea  fauna  will  be  discussed  in 
a  future  chapter.  It  will  suffice  at  present  to  mention 
in  order  the  few  data  which  gradually  prepared  the 
minds  of  naturalists  to  distrust  the  hypothesis  of  a 
zero  of  animal  life  at  a  limited  depth,  and  led  to  the 
recent  special  investigations.  In  the  year  1819  Sir 
John  Hoss  published  the  official  account  of  his  voyage 
of  discovery  during  the  year  1818  in  Baffin's  Bay.^ 
At  page  178  he  says,  "  In  the  meantime  I  was  em- 
ployed on  board  in  sounding  and  in  trying  the  cur- 
rent, and  the  temperature  of  tlie  water.  It  being 
perfectly  calm  and  smooth,  I  had  an  excellent  oppor- 
tunity of  detecting  these  important  objects.  Sound- 
ings were  obtained  correctly  in  1,000  fathoms, 
consisting  of  soft  mud,  in  which  there  were  worms, 
and,  entangled  on  the  sounding  line,  at  the  depth 
of  800  fathoms,  was  found  a  beautiful  Caput  Medusce 
(Eig.  1).  These  were  carefully  preserved,  and  will  be 
found  described  in  the  appendix."  This  was  in  lat. 
73°  37'  N.,  long.  77°  25'  W.,  on  the  1st  of  September, 
1818,  and  it  is,  so  far  as  I  am  aware,  the  first  recorded 
instance  of  living  animals  having  been  brought 
up  from  any  depth  approaching  1,000  fathoms. 
General  Sir  Edward  Sabine,  who  was  a  member  of 
Sir  John  Boss's  expedition,  has  kindly  furnished  Dr. 

^  A  Voyage  of  Discovery  made  under  the  Orders  of  the  Admiralty 
in  His  Majesty's  ships  ^Isabella'  and  'Alexander/  for  the  purpose 
of  exploring  Baffin's  Bay,  and  inquiring  into  the  Possibility  of  a 
ISTorth-west  Passage.  By  John  Eoss,  K.G.,  Captain  Royal  l!^avy. 
London,  1819. 


I 


CHAP.  I.]  INTRODUCTION.  [<) 

Carpenter  with  some  more  ample  particulars  of  tliis 


Fig.  1. — Asterophyton  linckii,  Muller  and  Troschel.     A  young  specimen  slightly 
enlarged.     No.  75. 


occurrence : 


.1  it  c 


The  ship  sounded  in  1,000  fathoms, 
mud,    hetween   one   and   two    miles  off    shore    (lat. 

^  Preliminary  Report,  by  Dr.  William  B.  Carpenter,  V.P.R.S.,  of 
Dredging  Operations  in  the  Seas  to  the  Korth  of  the  British  Islands, 
carried  on  in  Her  Majesty's  steam- vessel  'Lightning,'  by  Dr. 
Carpenter  and  Dr.  Wyville  Thomson.  (Proceedings  of  the  Royal 
Society,  1868,  p.  177.) 

C  2 


20  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

73°  37'  N.,  long.  77°  25'  W.) ;  a  magnificent  Asterias 
{Caput  Medusce)  was  entangled  by  the  line,  and 
brought  up  with  very  little  damage.  The  mud  was 
soft  and  greenish,  and  contained  specimens  of  Lum- 
hricus  tuhicola'  So  far  my  written  journal ;  but  I 
can  add,  from  a  very  distinct  recollection,  that  the 
heavy  deep-sea  weight  had  sunk,  drawing  the  line 
with  it,  several  feet  into  the  soft  greenish  mud, 
which  still  adhered  to  the  line  M^hen  brought  to 
the  surface  of  the  water.  The  star-fish  had  been 
entangled  in  the  line  so  little  above  the  mud  that 
fragments  of  its  arms,  which  had  been  broken  off  in 
the  ascent  of  the  line,  were  picked  up  from  amongst 
the  mud." 

Sir  James  Clark  Ross,  R.N.,  dredging  in  270 
fathoms,  lat.  73°  3'  S.,  long.  176°  &  E.,  reports:^ 
"  Corallines,  FlustrcB,  and  a  variety  of  invertebrate 
animals,  came  up  in  the  net,  showing  an  abundance 
and  great  variety  of  animal  life.  Amongst  these  I 
detected  two  species  of  JPycnogonum  ;  Idotea  baffini, 
hitherto  considered  peculiar  to  the  Arctic  seas ;  a 
Chiton,  seven  or  eight  bivalves  and  univalves,  an  un- 
known species  of  Gammarus,  and  two  kinds  of  Serpula 
adhering  to  the  pebbles  and  shells  ...  It  was  interest- 
ing amongst  these  creatures  to  recognize  several  that . 
I  had  been  in  the  habit  of  taking  in  equally  high! 
northern  latitudes  ;  and  although,  contrary  to  the 
general  belief  of  naturalists,  I  have  no  doubt  that, 
from  however  great  a  depth  we  may  be  enabled  to 
bring  up  the  mud  and  stones  of  the  bed  of  the  ocean. 


^  A  Voyage  of  Discovery  and  Research  in  the  Southern  and 
Antarctic  Regions  during  the  Years  1839-43.  By  Captain  Sir 
James  Clark  Ross,  R.N.      London,  1847. 


CHAP.  I.]  INTRODUCTION.  21 

we  shall  find  them  teeming  with  animal  life ;  the  ex- 
treme pressure  at  the  greatest  depth  does  not  appear 
to  affect  these  creatures ;  hitherto  we  have  not  heen 
able  to  determine  this  point  beyond  a  thousand 
fathoms,  but  from  that  depth  several  shell-fish  have 
been  brought  up  with  the  mud." 

On  the  28th  of  June  1845,  Mr.  Henry  Goodsir, 
who  was  a  member  of  Sir  John  Pranklin's  ill-fated 
expedition,  obtained  in  Davis'  Strait  from  a  depth  of 
300  fathoms,  ''  a  capital  haul, — mollusca,  Crustacea, 
asterida,  spatangi,  corallines,  &c."  ^  The  bottom  was 
composed  of  fine  green  mud  like  that  mentioned  by 
Sir  Edward  Sabine. 

About  the  year  1854  Passed-midshipman  Brooke, 
TJ.S.N.,  invented  his  ingenious  sounding  instrument 
for  bringing  up  samples  from  the  bottom.  It  only 
brought  up  a  small  quantity  in  a  quill.  These  trophies 
from  any  depth  over  1,000  fathoms  were  eagerly  sought 
for  bv  naturalists  and  submitted  to  searching:  micro- 
scopic  examination ;  and  the  result  was  very  surpris- 
ing. All  over  the  Atlantic  basin  the  sediment  brought 
up  was  nearly  uniform  in  character,  and  consisted 
almost  entirely  of  the  calcareous  shells,  whole  or  in 
fragments,  of  one  species  of  foraminifer,  Glohigerina 
hulloides  (Fig.  2).  Mixed  with  these  were  the  shells 
of  some  other  foraminifera,  and  particularly  a  little 
perforated  sphere,  Orbulina  tmiversa  (Fig.  3),  which 
in  some  localities  entirely  replaces  Glohigerina ; 
with  a  few  shields  of  diatoms,  and  spines  and 
trellised  skeletons  of  Radiolaria.  Some  soundings 
from  the    Pacific   were   of    the    same    character,    so 

1  Natural  History  of  the  British  Seas.  By  Professor  Edward 
Forbes  and  R.  Godwin- Austeu.    P.  ol. 


22  THE  DEPTHS  OF  THE  SEA  [chap.  i. 

that  it  seemed  probable  that  this  gradual  deposition 
of  a  line  uniform  organic  sediment  was  almost 
universal. 

Then  the  question  arose  whether  the  animals  which 
secreted  these  shells  lived  at  the  bottom,  or  whether 
they  floated  in  myriads  on  the  surface  and  in  tlie 
upper  zones  of  the  sea,  their  empty  shells  falling 
after  death  through  the  water  in  an  incessant  shower. 
Specimens  of  the  soundings  were  sent  to  the  eminent 


Fir,.  2.—Globigerina  btilloides,  D'Orbigny.     Highly  magnified. 

microscopists  Professor  Ehrenberg  of  Berlin  and  the 
late  Professor  Baily   of  West  Point.     On  the  moot 
question  these  two  naturalists  gave  opposite  opinions. 
Ehrenberg   contended   that   the  weight   of  evidence 
was  in  favour  of  their  having  lived  at  the  bottom,     i 
while  Baily  thought  it  was  not   probable   that   the    i 
animals    live    at    the   depths  where   the    shells    are     ' 
found,    but    that   they  inhabit   the   water   near  the    I 





GHAP.  I.]  INTRODUCTION.  23 

surface,  and  when  they  die  their  shells  settle  to  the 
bottom.^ 

The  next  high  authority  who  expressed  an  opinion 
was  Professor  Huxley,  and  he  was  very  guarded.  The 
samples  procured  by  Capt.  Dayman  in  the  'Cyclops,' 


Fio.  S.—Orhulina  universa,  D'Orbigny.    Highly  magnified. 

in  1857,  w^ere  submitted  to  him  for  examination,  and 
in  his  report  to  the  Admiralty^  in  1858  he  says  : — 

^  Explanations  and  Sailing  Directions  to  accompany  the  Wind  and 
Currents  Charts.  By  M.  F.  Maury,  LL.D.,  Lieut.  U.S.K,  Super- 
intendent of  the  National  Observatory.  6th  Edition.  Philadelphia, 
1864.     P.  299. 

^  Appendix  A  to  Deep  Sea  Soundings  in  the  North  Atlantic  Ocean 
between  Ireland  and  Newfoundland,  made  in  H.M.S.  'Cyclops,' 
Lieut.-Commander  Joseph  Dayman,  in  June  and  July  1857.  Pub- 
lished by  order  of  the  Lords  Commissioners  of  the  Admiralty. 
London,  1858. 


24  THE  DEPTHS  OF  THE  SEA,  [chap.  i. 

"  How  can  animal  life  be  conceived  to  exist  under 
such  conditions  of  light,  temperature,  pressure,  and 
aeration  as  must  obtain  at  these  vast  depths  ?  To  this 
one  can  only  reply  that  we  know  for  a  certainty  that 
even  very  highly- organized  animals  do  contrive  to  live 
at  a  depth  of  300  or  400  fathoms,  inasmuch  as  they 
have  been  brought  up  thence,  and  that  the  difference 
in  the  amount  of  light  and  heat  at  400  and  at  2,000 
fathoms  is  probably,  so  to  speak,  very  far  less  than 
the  difference  in  complexity  of  organization  between 
these  animals  and  the  humble  Protozoa  and  Proto- 
phyta  of  the  deep-sea  soundings.  I  confess,  though, 
as  yet,  far  from  regarding  it  proved  that  the  GIg- 
higerincB  live  at  these  depths,  the  balance  of  proba- 
bilities seems  to  me  to  incline  in  that  direction." 

In  1860  Dr.  Wallich  accompanied  Captain  Sir 
Leopold  McClintock  in  H.M.S.  'Bulldog'  on  her 
sounding  expedition  to  Iceland,  Greenland,  and  New- 
foundland, as  naturalist.  During  the  cruise  soundings 
were  taken,  and  specimens  of  the  bottom  were  brought 
up  from  depths  from  600  to  2,000  fathoms ;  many  of 
these  were  the  now  well-known  grey  *Globigerina  ooze,' 
while  others  were  volcanic  detritus  from  Iceland,  and 
clay  and  gravel  the  product  of  the  disintegration  of  the 
metamorphic  rocks  of  Greenland  and  Labrador.  On 
the  return  voyage,  about  midway  between  Cape  Pare- 
well  and  Rockall,  thirteen  star-fishes  came  up  from  a 
sounding  of  1,260  fathoms,  "  convulsively  embracing 
a  portion  of  the  sounding-line  which  had  been  payed 
out  in  excess  of  the  already  ascertained  depth,  and 
rested  for  a  sufficient  period  at  the  bottom  to  permit 
of  their  attaching  themselves  to  it."  On  his  return 
Dr.  Wallich  published  in  1862,  an  extremely  valuable 


CHAP.  I.]  INTRODUCTION.  25 

work  which  will  be  frequently  referred  to  hereafter, 
upon  *  The  Atlantic  Sea -bed.'  ^  He  warmly  advocated 
the  view  that  the  conditions  of  the  bottom  of  the  sea 
were  not  such  as  to  preclude  the  possibility  of  the 
existence  of  even  the  higher  forms  of  animal  life,  and 
discussed  fully  and  with  great  ability  the  arguments 
which  had  been  advanced  on  the  other  side.  The  first 
part  only  of  Dr.  Wallich's  book  appeared,  in  a  some- 
what costly  and  cumbrous  form,  and  it  scarcely  came 
into  the  hands  of  working  naturalists,  or  received  the 
attention  which  it  deserved.  At  the  time,  however,  it 
was  merely  an  expression  of  individual  opinion,  for 
no  new  facts  had  been  elicited.  Star-fishes  had  come 
up  on  several  previous  occasions  adhering  to  sounding- 
lines,  but  the  absolute  proof  was  still  wanting  that 
they  had  lived  upon  the  ground  at  the  depth  of  the 
sounding.  Dr.  Wallich  referred  the  star-fishes  procured 
to  a  well-known  littoral  species,  and  complicated  their 
history  somewhat  irrelevantly  Avith  the  disappearance 
of  the  '  Land  of  Buss.'  Portunately  the  artistic  if 
not  very  satisfactory  figure  which  he  gives  of  a  star- 
fish clinging  to  the  line  does  not  bear  out  his  deter- 
mination either  in  appearance  or  attitude,  but  suggests 
one  or  other  of  two  species  which  we  now  know  to 
be  excessively  abundant  in  deep  water  in  the  North 
Atlantic,  Ophiopholis  aculeata,  O.  F.  MiJLLER,  or 
Ophiacantha     spinulosa,     Mtjller     and    Troschel. 

^  The  North  Atlantic  Sea-bed  :  comprising  a  Diary  of  the  Voyage 
on  board  H.M.S.  *  Bulldog.'  in  1860;  and  Observations  on  the 
presence  of  Animal  Life,  and  the  Formation  and  Nature  of  Organic 
Deposits  at  great  Depths  in  the  Ocean.  By  G.  C.  Wallich,  M.D., 
F.L.S.,  F.G.S.,  &c.  Published  with  the  sanction  of  the  Lords  Com- 
missioners of  the  Admiralty.     London,  1862. 


26  THE  DEPTHS  OF  THE  SEA.  [chap.  i.    j 

Dr.  Wallicli's  is  the  only  book  which  discusses  fully 
and  systematically  the  various  questions  bearing 
upon  the  biological  relations  of  the  sea-bed,  and  his 
conclusions  are  in  the  main  correct. 

In  the  autumn  of  the  year  1860  Mr.  Tleeming 
Jenkin,  C.E.,  now  Professor  of  Engineering  in  the 
University  of  Edinburgh,  was  employed  by  the 
Mediterranean  Telegraph  Company  to  repair  their 
cable  between  Sardinia  and  Bona  on  the  coast  of 
Africa,  and  on  January  15,  1861,  he  gave  an  interest- 
ing account  of  his  proceedings  at  a  meeting  of  the 
Institution  of  Civil  Engineers.* 

This  cable  was  laid  in  the  year  1857.  In  1858  it 
became  necessary  to  repair  it,  and  a  length  of  about 
30  miles  was  picked  up  and  successfully  replaced. 
In  the  summer  of  1860  the  cable  completely  failed. 
On  taking  it  up  in  comparatively  shallow  water  on 
the  African  shore,  the  cable  w^as  found  covered  with 
marine  animals,  greatly  corroded,  and  injured  appa- 
rently by  the  trawling  operations  in  an  extensive 
coral  fishery  through  which  it  unfortunately  passed. 
It  was  broken  through  in  70  fathoms  water  a  few 
miles  from  Bona.  The  sea-end  was  however  recovered, 
and  it  was  found  that  the  cable  which  thence  traversed 
a  wide  valley  nearly  2,000  fathoms  in  maximum 
depth,  w^as  perfect  to  within  about  40  miles  of  Sar- 
dinia. It  was  then  picked  up  from  the  Sardinian  end, 
and  the  first  39  miles  were  as  sound  as  when  it  was 
first  laid  down.  At  this  distance  from  the  shore  there 
was  a  change  in  the  nature  of  the  bottom,  evidenced 
by  the  different  colour  of  the  mud,  and  the  wires  were 

^  Minutes  of  Proceedings  of  the  Institution  of  Civil  Engineers, 
with  Abstracts  of  the  Discussions.     Vol.  xx.  p.  81.     London,  1861. 


CHAP.  I.] 


INTRODUCTION. 


27 


much  corroded.  Shortly  afterwards  the  cable  gave 
way  in  a  depth  of  1,200  fathoms,  at  a  distance  of  one 
mile  from  the  spot  where  the  electrical  tests  showed 
that  the  cable  had  been  previously  broken. 

With  these  40  miles  of  cable  much  coral  and  many 
marine  animals  w^ere  brought  up,  but  it  did  not  appear 
that  their  presence  had  injured  the  cable,  for  they 
were  attached  to  the  sound  as  well  as  to  the  corroded 
portions.  On  his  return,  Mr.  Pleeming  Jenkin  sent 
specimens  of  the  animals  which  he  had  himself  taken 
from  the  cable,  noting  the  respective  depths,  to  Pro- 
fessor Allman,  E.E.S.  for  determination.  Dr.  Allman 
gives  a  list  of  fifteen  animal  forms,  including  the  ova 
of  a  cephalopod,  foimd  at  depths  of  from  70  to  1,200 


Fig.  4. — Caryophylliahorealis,  Fletaing.     Twice  the  natural  size.     No.  45. 

fathoms.  On  other  portions  of  the  cable  species  of 
Grantia,  JPlumularia,  Gorgonia,  Gary ophy Ilia,  Alcy- 
onium,  Cellepora,  Retepora,  Eschara,  Salicornaria, 
Ascidia,  Lima,  and  Serpula.    I  observe  from  Professor 


28  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

Eleeming  Jenkin's  private  journal,  which  he  has 
kindly  placed  in  my  hands  for  reference,  that  an 
example  of  Caryophyllia,  a  true  coral  (Fig.  4),  was 
found  naturally  attached  to  the  cahle  at  the  point 
where  it  gave  way;  that  is  to  say,  at  the  bottom  in 
1,200  fathoms  water. 

Some  portions  of  this  cahle  subsequently  came  into 
the  custody  of  M.  Mangon,  Professor  at  the  Ecole 
des  Fonts  et  Chaussees  in  Paris,  and  were  examined 
by  M.  Alphonse  Milne-Edwards,  who  read  a  paper 
upon  the  organisms  attached  to  them,  at  the  Academy 
of  Sciences,  on  the  15th  of  July,  1861/  After  some 
introductory  remarks  which  show  that  he  is  thoroughly 
aware  of  the  value  of  this  observation  as  a  final 
solution  of  the  vexed  question  of  the  existence  of 
animal  life  at  depths  in  the  sea  greatly  beyond  the 
supposed  'zero*  of  Edward  Eorbes,  M.  Milne- 
Edwards  gives  a  list  of  the  animals  which  he  found  on 
the  cable  from  the  depth  of  1,100  fathoms.  The  list 
includes  Mm^ex  lamellosus,  Cristofori  and  Jan,  and 
Craspedotus  limbatus,  Philippi,  two  univalve  shells 
allied  to  the  whelk ;  Ostrea  cochlear,  Poli,  a  small 
oyster  common  below  40  fathoms  throughout  the 
Mediterranean;  Fecten  testce,  Bivona,  a  rare  little 
clam ;  Car yophy Ilia  borealis,  Fleming,  or  a  nearly 
allied  species,  one  of  the  true  corals  ;  and  an  unde- 
scribed  coral  referred  to  a  new  genus  and  species 
under  the  name  of  Thalassiotrochiis  telegraphicus, 
A.  Milne-Edwards. 

^  Observations  sur  I'Existence  de  divers  Mollusques  et  Zoophytes  a 
de  tres  grandes  profondeurs  dans  la  Mer  Mediterranee :  Annales  des 
Sciences  Naturelles;  quatrieme  serie — Zoologie.  Tome  xv.  p.  149. 
Paris,  1861. 


CHAP.  I.]  INTRODUCTION.  29 

It  is  right,  however,  to  state  that  Prof.  Eleeming 
Jenkin's  notes  refer  to  only  one  or  two  species,  and 
especially  to  Car yopJiy Ilia  horealis,  as  attached  to  the 
cable  at  a  depth  of  upwards  of  ]  ,000  fathoms.  From 
this  depth  he  took  examples  of  Caryophyllia  with  his 
own  hands,  hut  he  suspects  that  specimens  from  the 
shallower  water  may  have  got  mixed  with  those  from 
the  deeper  in  the  series  in  the  possession  of  M. 
Mangon,  and  that  therefore  M.  Milne-Edwards'  list  is 
not  entirely  trustworthy. 

Up  till  this  time  all  observations  with  reference  to 
the  existence  of  living  animals  at  extreme  depths  had 
been  liable  to  error,  or  at  all  events  to  doubt,  from 
two  sources.  The  appliances  and  methods  of  deep- 
sea  sounding  were  imperfect,  and  there  was  always 
a  possibility,  from  the  action  of  deep  currents  upon 
the  sounding  line  or  from  other  causes,  of  a  greater 
depth  being  indicated  than  really  existed ;  and  again, 
although  there  was  a  strong  probability,  there  was 
no  absolute  certainty  that  the  animals  adhering  to 
the  line  or  entangled  on  the  sounding  instrument 
had  actually  come  up  from  the  bottom.  They  might 
have  been  caught  on  the  way. 

Before  laying  a  submarine  telegraphic  cable  its 
course  is  carefully  surveyed,  and  no  margin  of  doubt 
is  left  as  to  the  real  depth.  Fishing  the  cable  up  is  a 
delicate  and  difficult  operation,  and  during  its  progress 
the  depth  is  checked  again  and  again.  The  cable  lies 
on  the  ground  throughout  its  whole  length.  The 
animal  forms  upon  which  our  conclusions  are  based 
are  not  sticking  loosely  to  the  cable,  under  circum- 
stances which  might  be  accounted  for  by  their  having 
been  entangled  upon  it  during  its  passage  through  the 


30  THE  DEPTHS  OF  THE  SEA,  [chap.  i. 

water,  but  they  are  moulded  upon  its  outer  surface  or 
cemented  to  it  by  calcareous  or  horny  excretions,  and 
some  of  them,  such  as  the  corals  and  bryozoa,  from 
what  Ave  know  of  their  history  and  mode  of  life,  must 
have  become  attached  to  it  as  minute  germs,  and  have 
grown  to  maturity  in  the  position  in  which  they  were 
found.  I  must  therefore  regard  this  observation  of 
Mr.  Eleeming  Jenkin  as  having  afforded  the  first 
absolute  proof  of  the  existence  of  highly-organized 
animals  living  at  depths  of  upwards  of  1,000  fathoms. 

During  the  several  cruises  of  H.M.  ships  'Light-   1 
ning  '  and  '  Porcupine '  in  the  years  1868,  1869,  and    i 
1870,^  fifty-seven  hauls  of  the  dredge  were  taken  in    \ 
the  Atlantic  at  depths  beyond  500  fathoms,  and  sixteen 
at  depths  beyond  1,000  fathoms,  and  in  all  cases  life  was 
abundant.   In  1869  we  took  two  casts  in  depths  greater 
than  2,000  fathoms.     In  both  of  these  life  was  abun- 
dant ;  and  with  the  deepest  cast,  2,435  fathoms,  off 
the  mouth  of  the  Bay  of  Biscay,  we  took  living,  well- 
marked  and  characteristic  examples  of  all  of  the  five  | 
invertebrate  sub-kingdoms.    And  thus  the  question  of  |i 

^  Preliminary  Eeport,  by  Dr.  William  Carpenter,  V.P.E  S.,  of  i 
Dredging  Operations  in  the  Seas  to  the  north  of  the  British  Islands,  ' 
carried  on  in  Her  Majesty's  steam-vessel  '  Lightning '  by  Dr.  Carpenter  !' 
and  Dr.  Wyville  Thomson,  Professor  of  IS'atural  History  in  Queen's  ' 
College,  Belfast.     (Proceedings  of  the  Royal  Society  of  London,  1868.) 

Preliminary  Report  of  the  Scientific  Exploration  of  the  Deep  Sea 
in  H.M.  surveying-vessel  'Porcupine,'  during  the  Summer  of  1869. 
Conducted  by  Dr.  Carpenter,  Y.P.R.S.,  J.  Gwyn  Jeifreys,  P.R.S.,  and 
Professor  Wyville  Thomson,  LL.D.,  F.R.S.  (Proceedings  of  the  Royal 
Society  of  London,  1870.) 

Report  of  Deep  Sea  Researches  carried  on  during  the  months  of 
July,  August,  and  September  1870,  in  H.M.  surveying-ship  '  Porcu- 
pine,' by  W.  B.  Carpenter,  M.D.,  F.R.S.,  and  J.  Gwyn  Jeffreys,  F.R.S. 
(Proceedings  of  the  Royal  Society  of  London,  1870.) 


CHAP.  I.]  INTRODUCTION.  31 

the  existence  of  abundant  animal  life  at  the  bottom 
of  the  sea  has  been  finally  settled  and  for  all  depths, 
for  there  is  no  reason  to  suppose  that  the  depth  any- 
where exceeds  between  three  and  four  thousand 
fathoms ;  and  if  there  be  nothing  in  the  conditions  of 
a  depth  of  2,500  fathoms  to  prevent  the  full  develop- 
ment of  a  varied  fauna,  it  is  impossible  to  suppose 
that  even  an  additional  thousand  fathoms  would  make 
any  great  difference. 

The  conditions  which  might  be  expected  principally 
to  affect  animal  life  at  great  depths  of  the  sea  are 
pressure,  temperature,  and  the  absence  of  light  which 
apparently  involves  the  absence  of  vegetable  food. 

After  passing  a  zone  surrounding  the  land,  which  is 
everywhere  narrow  compared  with  the  extent  of  the 
ocean,  through  which  the  bottom  more  or  less  abruptly 
shelves  downwards  and  the  water  deepens ;  speaking 
very  generally,  the  average  depth  of  the  sea  is 
2,000  fathoms,  or  about  two  miles  ;  as  far  below 
the  surface  as  the  average  height  of  the  Swiss  Alps. 
In  some  places  the  depth  seems  to  be  considerably 
greater,  possibly  here  and  there  nearly  double  that 
amount ;  but  these  abysses  are  certainly  very  local, 
and  their  existence  is  even  uncertain,  and  a  vast  por- 
tion of  the  area  does  not  reach  a  depth  of  1,500 
fathoms. 

The  enormous  pressure  at  these  great  depths  seemed 
at  first  sight  alone  sufficient  to  put  any  idea  of  life 
out  of  the  question.  There  was  a  curious  popular 
notion,  in  which  I  well  remember  sharing  when  a  boy, 
that,  in  going  down,  the  sea- water  became  gradually 
under  the  pressure  heavier  and  heavier,  and  that  all 
the  loose  things  in  the  sea  floated  at  different  levels. 


32  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

according  to  their  specific  weight :  skeletons  of  men, 
anchors  and  shot  and  cannon,  and  last  of  all  the 
broad  gold  pieces  wrecked  in  the  loss  of  many  a 
galleon  on  the  Spanish  Main ;  the  whole  forming  a 
kind  of  '  false  bottom  '  to  the  ocean,  beneath  which 
there  lay  all  the  depth  of  clear  still  water,  which 
was  heavier  than  molten  gold. 

The  conditions  of  pressure  are  certainly  very  extra- 
ordinary. At  2,000  fathoms  a  man  would  bear  upon  his 
body  a  weight  equal  to  twenty  locomotive  engines,  each 
with  a  long  goods  train  loaded  with  pig  iron.  We  are 
apt  to  forget,  however,  that  water  is  almost  incom- 
pressible, and  that  therefore  the  density  of  sea-water 
at  a  depth  of  2,000  fathoms  is  scarcely  appreciably 
increased.  At  the  depth  of  a  mile,  under  a  pressure 
of  about  159  atmospheres,  sea-water,  according  to  the 
formula  given  by  Jamin,  is  compressed  by  the  ttt  of 
its  volume  ;  and  at  twenty  miles,  supposing  the  law  of 
the  compressibility  to  continue  the  same,  by  only  |  of 
its  volume — that  is  to  say,  the  volume  at  that  depth 
would  be  T  of  the  volume  of  the  same  weight  of  water 
at  the  surface.  Any  free  air  suspended  in  the  water, 
or  contained  in  any  compressible  tissue  of  an  animal 
at  2,000  fathoms,  would  be  reduced  to  a  mere  fraction 
of  its  bulk,  but  an  organism  supported  through  all  its 
tissues  on  all  sides,  within  and  without,  by  incom- 
pressible fluids  at  the  same  pressure,  would  not 
necessarily  be  incommoded  by  it.  We  sometimes 
find  when  we  get  up  in  the  morning,  by  a  rise  of  an 
inch  in  the  barometer,  that  nearly  half  a  ton  has  been 
quietly  piled  upon  us  during  the  night,  but  we  expe- 
rience no  inconvenience,  rather  a  feeling  of  exhilara- 
tion and  buoyancy,  since  it  requires  a  little  less  exer- 


CHAP.  I.]  IXTRODUCTIOX.  33 

tion  to  move  our  bodies  in  the  denser  medium.  We  are 
already  familiar,  chiefly  through  the  researches  of  the 
late  Professor  Sars,  with  a  long  list  of  animals  of  all 
the  invertebrate  groups  living  at  a  depth  of  300  to 
400  fathoms,  and  consequently  subject  to  a  pressure 
of  1,120  lbs.  on  the  square  inch  ;  and  off  the  coast  of 
Portugal  there  is  a  great  fishery  of  sharks  (^Centros- 
cymnus  coelolepis,  Boc.  and  Cap.),  carried  on  beyond 
that  depth. 

If  an  animal  so  high  in  the  scale  of  organization 
as  a  shark  can  bear  without  inconvenience  the 
pressure  of  half  a  ton  on  the  square  inch,  it  is  a 
sufficient  proof  that  the  pressure  is  applied  under 
circumstances  which  prevent  its  aflPecting  it  to  its 
prejudice,  and  there  seems  to  be  no  reason  why 
it  should  not  tolerate  equally  well  a  pressure  of 
one  or  two  tons.  At  all  events  it  is  a  fact  that 
the  animals  of  all  the  invertebrate  classes  which 
abound  at  a  depth  of  2,000  fathoms  do  bear  that 
extreme  pressure,  and  that  they  do  not  seem  to  be 
affected  by  it  in  any  way.  We  dredged  at  2,435 
fathoms  Scrohicularia  nitida,  MtJLLEii,  a  species 
which  is  abundant  in  six  fathoms  and  at  all  inter- 
mediate depths,  and  at  2,090  fathoms  a  large  Ftisus, 
with  species  of  many  genera  which  are  familiar  at 
moderate  depths.  Although  highly  organized  animals 
may  live  when  permanently  subjected  to  these  high 
pressures,  it  is  by  no  means  certain  that  they  could 
survive  the  change  of  condition  involved  in  the  pres- 
sure being  suddenly  removed.  Most  of  the  mollusca 
and  annelids  brought  up  in  the  dredge  from  beyond 
1,000  fathoms  were  either  dead  or  in  a  very  sluggish 
state.     Some  of  the  star-fishes  moved  for  some  time 

D 


34  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

feebly,  and  the  spines  and  pedicellarise  moved  on  the 
shells  of  the  urchins,  but  all  the  animals  had  evi- 
dently received  from  some  cause  their  death- shock. 
Dr.  Perceval  Wright  mentions^  that  all  the  sharks 
brought  up  by  the  long  lines  from  500  fathoms  in 
Setubal  Bay  are  dead  when  they  reach  the  surface. 

Various  methods  have  been  proposed  to  test  the 
actual  pressure  at  great  depths,  but  as  all  the  elements 
in  the  calculation  are  well  known,  it  is  easier  to  work 
out  the  question  in  the  study  than  in  the  field.  A 
neat  instrument  was  constructed  for  the  American 
Coast  Survey.  A  brass  piston  or  plunger  was  fitted 
accurately  into  a  cylindrical  hole  in  the  wall  of  a  brass 
water-tight  chamber.  The  chamber  was  completely 
filled  with  water,  and  a  clasping  index  on  the  plunger 
marked  to  what  extent  the  plunger  had  been  driven 
into  the  water  contained  in  the  chamber  by  the 
extreme  pressure.  The  required  indication  is  no 
doubt  given,  but  such  an  instrument  is  at  the  same 
time  an  extremely  delicate  thermoscope,  and  until 
lately  there  has  been  no  perfect  means  of  correcting 
for  temperature.  A  more  important  application  of 
the  pressure  gauge  is  to  check  the  accuracy  of  deep 
soundings.  Probably  the  best  arrangement  which 
has  been  proposed  for  the  purpose  is  a  long  capil- 
lary glass  tube,  calibrated  and  graduated  to  milli- 
metres, open  at  one  end,  and  provided  with  a  moveable 
index  to  show  to  what  amount  the  air  contained  in 
the  tube  has  been  compressed  by  the  entrance  of  the 
water.     The  principal  objection  to  this  device  is  the 

^  Notes  on  Deep  Sea  Dredging,  by  Edward  Perceval  Wright,  M.D., 
F.L.S.,  Professor  of  Zoology,  Trinity  College,  Dublin.  (Annals  and 
Magazine  of  Natural  History,  December  1868.) 


CHAP.  1.]  INTRODUCTION.  35 

great  difficulty  in  arranging  an  index  which  will 
measure  with  accuracy  the  extremely  small  space  into 
which  even  a  long  column  of  air  is  compressed  when 
the  pressure  becomes  very  great.  It  can  scarcely  be 
made  available  beyond  1,000  fathoms  (200  atmo- 
spheres). 

We  have  in  Sir  John  Herschel's  '  Physical  Geo- 
graphy,'^ and  in  Dr.  Wallich's  'Atlantic  Sea-bed,'^ 
where  it  is  given  in  the  fullest  dstail,  the  doctrine  of 
the  distribution  of  deep-sea  temperature  as  it  seems 
to  have  been  almost  universally  adopted  up  till  the 
time  of  the  cruise  of  the  '  Lightning.'  It  was  gene- 
rally understood  that  while  the  surface  temperature, 
which  depended  upon  direct  solar  radiation,  the 
direction  of  currents,  the  temperature  of  winds,  and 
other  temporary  causes,  might  vary  to  any  amount ; 
at  a  certain  depth  the  temperature  was  permanent  at 
4°  C,  the  temperature  of  the  greatest  density  of  fresh 
water.  It  is  singular  that  this  belief  should  have  met 
with  so  general  acceptance,  for  so  early  as  the  year 
1833  M.  Depretz^  determined  that  the  temperature 
of  the  maximum  density  of  sea- water,  which  contracts 
steadily  till  just  above  its  freezing-point,  is  — 3°'67  C. ; 
and  even  before  that  time  observations  of  sea-tempe- 
ratures at  great  depths,  which  were  certainly  trust- 
worthy within  a  few  degrees,  had  indicated  severa- 
degrees  below  the  freezing-point  of  fresh  water. 

The  question  of  the  distribution  of  heat  in  the  sea, 

"^  Physical  Geography ;  from  the  "  Encyclopaedia  Britannica."     By 
Sir  John  F.  W.  Herschel,  Bart.  KH.  &c.  &c.,  p.  45.  Edinburgh,  1861. 

2  Atlantic  Sea-bed,  p.  98. 

^  Recherches  sur  le  Maximum  de  Densite  des  Dissolutions  aqueuses. 
(Annales  de  Chimie,  tome  Ixx.  1833,  p.  54.) 

D  2 


36  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

which  is  one  of  the  greatest  interest  in  connection 
with  the  distribution  of  marine  animals,  will  be  fully 
discussed  in  a  future  chapter.  The  broad  conclusions 
to  which  we  have  been  led  by  late  investigations  are, 
that  instead  of  there  being  a  permanent  deep  layer  of 
Avater  at  4°  C.  the  average  temperature  of  the  bottom 
of  the  deep  sea  in  temperate  and  tropical  regions  is 
about  0°  C,  the  freezing-point  of  fresh  water ;  and  that 
there  is  a  general  surface  movement  of  warm  water, 
produced  probably  by  a  combination  of  various  causes, 
from  the  equatorial  regions  towards  the  poles,  and  a 
slow  under-current,  or  rather  indraught,  of  cold  water 
from  the  poles  towards  the  equator.  Prom  cases 
which  are  recorded,  chiefly  by  the  earlier  American 
sounding  expeditions,  of  the  sounding-line  having  been 
run  out  into  long  loops  in  soundings  where,  from  the 
nature  of  the  sea-bed,  the  bottom  water  appeared. to 
be  still,  it  would  seem  that  there  are  also  in  some 
places  intermediate  currents ;  but  Avith  reference  to 
their  limits  and  distribution  we  have  as  yet  no  data. 
That  a  cold  flow  from  the  polar  seas  passes  over  the 
bottom  seems  to  be  proved  by  the  fact  that  in  all 
parts  of  the  world  wherever  deep  temperature  sound- 
ings have  been  taken,  from  the  arctic  circle  to  the 
equator,  the  temperature  sinks  with  increasing  depth, 
and  is  lower  at  the  bottom  than  the  normal  tempera- 
ture of  the  crust  of  the  earth ;  an  evidence  that  a 
constantly  renewed  supply  of  cold  water  is  cooling  ; 
down  the  surface  of  the  crust,  which,  being  a  bad  con- 
ductor, does  not  transmit  heat  with  sufficient  rapidity  j 
to  affect  perceptibly  the  temperature  of  the  cold  in-  j 
draught.  It  is  probable  that  in  winter,  in  those  parts  | 
of  the  arctic  sea  Avhich  are  not  directly  influenced  by  I 


CHAP.  I.]  INTRODUCTION.  3j 

the  northern  extension  of  the  gulf  stream,  the  whole 
column  of  water  from  the  surface  to  the  bottom  is 
reduced  to  the  lowest  temperature  which  it  will  bear 
without  freezing,  and  is  thus  an  ample  source  of  the 
coldest  water  of  the  highest  specific  gravity. 

The  proof  that  the  flow  of  the  cold  indraught  is 
almost  secular  in  its  slowness,  is  that  over  a  large 
portion  of  the  ocean  where  the  low  bottom  tempera- 
ture is  known  to  prevail,  the  sea-bed  is  covered  with 
a  light  fleecy  deposit  of  microscopic  organisms  of 
great  delicacy,  into  which  the  sounding-lead  has  in 
some  instances  sunk  several  feet,  and  which  must 
inevitably  be  drifted  away  by  a  current  of  appreciable 
velocity.  In  all  places  where  any  perceptible  current 
exists,  the  bottom  consists  of  sand  or  mud  or  gravel 
and  rolled  pebbles.  In  some  cases  also,  sounding  in 
the  deep  water  of  the  mid- Atlantic,  the  line,  after 
running  out  greatly  in  excess  of  the  depth,  has  been 
found  to  have  coiled  itself  in  a  tangled  mass  right 
over  the  lead — a  proof  of  almost  absolute  stillness. 

In  some  places,  owing  to  the  conformation  of  the 
neighbouring  land  or  of  the  sea-bottom,  warm  and 
cold  currents  are  circumscribed  and  localized,  and  this 
sometimes  gives  us  the  singular  phenomenon  of  a 
patch  or  stripe  of  warm  and  a  patch  of  cold  sea  meet- 
ing in  an  invisible  but  very  definite  line.  There  is  a 
curious  instance  of  this  in  the  '  cold  wall '  which 
defines  the  western  border  of  the  gulf  stream  along 
the  coast  of  Massachusetts,  and  another  scarcely  less 
marked  which  we  discovered  during  the  trial  cruise 
of  the  '  Lightning  '  has  been  fully  described  by  Dr. 
Carpenter  in  his  report  of  that  cruise,  and  will  be 
referred  to  hereafter. 


38  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

In  moderate  depths  sometimes  the  whole  mass  of 
water  from  the  surface  to  the  bottom  is  abnormally 
warm,  owing  to  the  movement  in  a  certain  direction 
of  a  great  body  of  warm  water,  as  in  the  '  warm  area ' 
to  the  north-west  of  the  Hebrides ;  and  sometimes  the 
whole  body  of  water  is  abnormally  cold,  as  in  the 
'  cold  area  '  between  Scotland  and  Pseroe,  and  in  the 
northern  part  of  the  German  Ocean.  In  deep  water 
however,  after  the  first  few  hundred  fathoms,  the 
thermometer  usually  sinks  gradually  and  very  slowly 
till  it  reaches  its  minimum  at  the  bottom,  a  little 
above  or  below  the  zero  of  the  centigrade  scale. 

The  temperature  of  the  sea  apparently  never  sinks 
at  any  depth  below  — 3°*5  C,  a  degree  of  cold  which, 
singularly  enough,  is  not  inconsistent  with  abundant 
and  vigorous  animal  life,  so  that  in  the  ocean,  except 
perhaps  within  the  eternal  ice-barrier  of  the  antarctic 
pole,  life  seems  nowhere  to  be  limited  by  cold.  But 
although  certain  sea-animals — many  of  them,  such  as 
the  siphonophora,  the  salpse,  and  the  ctenophorous 
medusae,  of  the  most  delicate  and  complicated  organiza- 
tion— are  tolerant  of  such  severe  cold,  it  would  appear 
to  be  temperature  almost  entirely  w^hich  regulates  the 
distribation  of  species.  The  nature  of  the  ground 
can  have  little  to  say  to  it,  for  on  every  line  of  coast 
of  any  extent  almost  every  condition  and  every  kind 
of  sediment  is  usually  represented.  From  their  inha- 
biting a  medium  which  differs  but  little  in  weight 
from  the  substance  of  their  bodies,  and  from  the  great 
majority  of  them  producing  free-moving  larvae  or  fry 
in  vast  numbers  which  are  floated  along  from  place 
to  place  by  currents,  marine  animals  would  seem  to 
have  every  possible  chance  of  extending  their  area. 


CHAP.  1.]  INTRODUCTION.  39 

and  yet  the  geographical  distribution  of  most  of  the 
shallow- water  species  is  well  defined,  and  frequently 
somewhat  restricted.  Unfortunately  we  know  as  yet 
very  little  about  the  general  distribution  of  marine 
animals.  Except  along  the  coasts  of  Britain  and 
Scandinavia,  a  part  of  the  North  American  coast,  and 
j  a  part  of  the  Mediterranean,  we  know  absolutely 
'  nothing  beyond  the  shore  zone,  or  at  all  events  beyond 
10  or  15  fathoms.  What  little  we  do  know  is  con- 
I  fined  almost  entirely  to  the  mollusca,  and  is  due,  not 
so  much  to  scientific  research  as  to  the  commercial 
value  which  the  acquisitive  zeal  of  conchologists  has 
placed  upon  rare  shells.  It  may  be  supposed,  how- 
ever, that  the  same  laws  which  regulate  the  distri- 
bution of  littoral  and  sub-littoral  mollusca,  afPect  in 
like  manner  that  of  shallow-water  annulosa,  echino- 
derms,  and  coelent crates ;  indeed,  from  the  scattered 
observations  which  have  been  made  on  the  distribu- 
tion of  these  latter  groups,  it  seems  certain  that  such 
is  the  case. 

Woodward^  regarded  the  marine  mollusca  as  occupy- 
ing eighteen  well-defined  '  provinces,'  fulfilling  more 
or  less  completely  the  condition  of  having  at  least  one- 
half  of  the  species  peculiar  to  the  province.  Edward 
Eorbes  defined  twenty-five  such  'regions;'  but  it  must 
be  remembered  that  in  both  cases  at  least  three- fourths 
of  the  number  of  areas  defined  were  based  upon  the 
most  imperfect  knowledge  of  the  larger  and  more  con- 
spicuous shore  shells  only.  It  has  been  constantly 
observed  in  the  few  cases  confined  entirely  to  the 
shores  of  the  North  Atlantic  and  the  Mediterranean, 

'  A  Manual  of  the  Mollusca.  By  S.  P.  Woodward.  London,  1851. 
P.  354. 


40  THE  DEFTHS  OF  THE  SEA.  [chap.  i. 

in  which  dredging  has  been  attempted  at  any  consider- 
able depth,  say  30  or  40  fathoms,  that  the  number  oi 
species  common  to  the  province  dredged  and  to  the] 
province   to   the   north    of   it,    is   greatly   increased 
by  the  investigation  being  carried  into  a  deeper  zone.^j 
Thus    in    the    lusitanian    province   Mr.    McAndrei 
dredged  off  the  coast  of  Galicia   and  Asturias,   212] 
species,  50  per  cent,  of  which  were  common  to  the 
coast  of  Norway ;    and  off  the  south   of  Spain   3351 
species  were  obtained,   of  which  28  per  cent,   w^ere] 
common  to  Norway    (boreal   province),   and  51  pei 
cent,  to  Britain  (chiefly  Celtic  province).     The  shells 
common  to  the  two  or  three  provinces  were  chiefly 
those  dredged  from  considerable  depths.     The  littoral 
forms  had  a  much  more  distinct  aspect.    The  moUusca 
of  the    '  Porcupine '    expedition   have  not   yet  been 
thoroughly  worked  out.     They  are  in  the  hands  of 
Mr.  Gwyn  Jeffreys,  and  his  preliminary  reports  give  a 
most  interesting  forecast  of  w^hat  we  may  expect  when 
his  labour  is  completed.      He  announces  something 
like  250  new  species.     Some  of  the  more  interesting 
of  these,  and  the  general  phenomena  of  their  distri- 
bution, will  be  referred  to  in  a  future  chapter. 

The  echinoderms  of  the  expedition  are  more  limited 
in  number,  and  have  already  been  examined  by  the 
writer  with  some  care.  The  general  distribution  of 
the  Echinodermata  is  not  so  w^ell  known  as  that  of  the 
Mollusca.  There  are  many  littoral  and  sub -littoral 
species.  Many  of  these  are  local,  but  many  have  a 
wide  geographical  distribution,  usually  along  what 
Edward  Eorbes  calls  a  '  homoiozoic  belt,'  a  belt  of 
nearly  similar  circumstances  of  climate  extending 
^  Woodward,  loc.  cit.  p.  362. 


CHAP.  1.]  INTRODUCTION.  4 1 

tlirougli  many  degrees  of  longitude,  but  few  of  latitude. 
•  As  a  class,  however,  they  prefer  a  depth  rather  beyond 
20  fathoms,^  beyond  the  reach  of  very  violent  climatic 
vicissitudes.  They  are  conspicuous  things,  showing 
usually  sufficiently  bold  specific  characters,  and  thus 
they  are  less  liable  to  confusion  than  most  other  groups. 
They  involve  in  their  history  and  economy  several  of 
the  principal  questions  discussed  in  this  volume;  while 
giving,  therefore,  such  a  brief  sketch  as  the  space  at 
my  disposal  and  the  amount  of  my  present  informa- 
tion may  permit,  of  the  additions  which  have  been 
made  during  our  dredging  cruises  to  the  knowledge 
of  the  other  invertebrate  classes,  I  will  use  the  echi- 
noderms  and  the  protozoa  principally  for  the  purpose 
of  general  illustration. 

Littoral  and  shallow-water  species  of  animals  must 
be  much  more  liable  to  have  their  migrations  inter- 
rupted by  'natural  barriers,'  such  as  deep  water 
through  which  they  cannot  pass,  or  currents  of 
warmer  or  of  colder  water;  they  must  likewise  be 
much  more  affected  by  local  circumstances,  such  as 
extreme  differences  between  summer  and  winter  tem- 
perature ;  so  that  they  might  be  expected  to  be  more 
circumscribed  and  local  in  their  distribution  than  the 
denizens  of  greater  depths — and  they  certainly  are  so. 
The  conditions  of  the  bottom  in  the  zone  from  20  to 
50  fathoms  are  much  more  equable  than  near  the 
surface.  Direct  solar  radiation  in  temperate  regions 
affects  this  zone  very  slightly,  so  that   it  probably 

^  Distribution  of  Marine  Life.  By  Professor  Edward  Forbes,  F.R.S., 
President  of  tbe  Geological  Society.  (From  the  Physical  Atlas  of 
K^atural  Phenomena,  by  Alexander  Keith  Johnston,  F.E.G.S.,  &c. 
Edinburgh,  1854.) 


42  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

maintains  nearly  the  same  conditions  of  temperature 
through  many  degrees  of  latitude;  and  when  as  it 
passes  southwards  it  does  become  gradually  affected 
by  increasing  warmth,  it  may  be  supposed  merely  to 
sink  a  few  fathoms  deeper,  carrying  its  conditions  and 
its  fauna  along  with  it.  Por  example,  animal  forms 
which  abound  in  the  Celtic  province  at  25  fathoms 
with  a  mean  temperature  of  10°  C,  may  be  expected  in 
greatest  number  in  perhaps  40  or  50  fathoms,  with 
the  same  temperature,  in  the  lusitanian  province. 
Such  a  zone  may  thus  be  continuous  for  a  great  dis- 
tance, while  the  surface  climate  has  been  altering 
greatly,  and  the  migrations  of  littoral  forms  have 
been  again  and  again  interrupted.  But  the  deeper 
zone  also  sometimes  meets  with  a  *  natural  barrier,' 
as  at  the  line  of  junction  between  the  warm  and  cold 
areas  already  mentioned;  which  causes  a  curious  sift- 
ing out  of  those  species  which  are  intolerant  of  a 
change  of  temperature.  Thus  the  fauna  of  the  tem- 
perate northward  flow  of  water  off  the  west  coast  of 
Scotland  is  materially  different  from  that  of  the  cold 
indraught  along  the  east  coast. 

If  there  be  this  overlapping  between  the  lusitanian 
and  Celtic  provinces,  the  same  relation  may  be  antici- 
pated between  our  own  and  the  boreal  province ;  and 
it  is  well  known  that  this  is  the  case,  for  the  great 
majority  of  the  mollusca  which  have  been  dredged  by 
McAndrew,  Barlee,  and  especially  by  Gwyn  Jeffreys, 
from  depths  below  50  fathoms,  are  identical  with  those 
found  in  shallower  water  on  the  Scandinavian  coast. 
Our  recent  work,  while  it  has  brought  out  more  fully 
the  overlapping,  has  gone  much  farther  towards  the 
indication  of  a  general  law. 


CHAP.  I.]  INTRODUCTION,  43 

It  seems  probable  that  the  distribution  of  marine 
animals  is  determined  by  the  extremes  of  temperature 
rather  than  by  the  means.  The  mean  winter  tempera- 
ture of  the  surface  and  of  moderate  depths  off  the 
north  coast  of  Norway  is  about  2°  C,  and  the  extreme 
about  0°  C. ;  and  on  the  coast  of  Greenland  the  mean 
sinks  to  — 1°  C,  and  the  extreme  to  — 3°  G. 

The  temperature  of  the  trough  between  Scotland 
and  Pseroe  at  the  depth  of  500  fathoms  is  from  0°  to 
—1°  C,  and  we  find  in  that  trough,  along  with  many 
undescribed  forms  which  are  special  to  very  deep 
water,  every  one  of  the  echinoderms  hitherto  found 
on  the  coast  of  Scandinavia  and  Greenland,  with  the 
single  exception,  I  believe,  of  Ophioglypha  stuwitzii,  a 
shallow-water  Greenland  form  among  the  ophiurids, 
and  of  one  or  two  holothurids  which  have  as  yet 
evaded  us. 

The  temperature  of  the  telegraphic  plateau  at  1,000 
to  2,000  fathoms  is  apparently  usually  from  3°  to  2°  C, 
and  at  2,500  fathoms  in  the  Bay  of  Biscay  it  is  2°  C. 
From  800  to  2,000  fathoms  all  along  the  west  coasts 
of  Scotland,  Ireland,  and  France,  we  have  dredged 
Scandinavian  echinoderms  in  abundance,  and   from 
the  deep  water  as  far  south  as  the  coast  of  Portugal 
\  I  have  received  examples  of  some  of  the  best  marked 
northern  forms,  such  as  Echimts  elegans,  ~D.  and  K.; 
I   Toxopneustes  drobachiensis,  O.  F.  Muller  ;  Brissopsis 
I  lyrifera,  Forbes  ;   Tripylus  fragilis,  D.  and  K. ;  the 
I  magnificent  Brisinga  coronata,  G.  O.  Sars  (Fig.  7), 
I   and  B,  endecacnemos^  Absjornsen;   Bter aster  mili- 
tarise M.  and  T. ;   Ophiacantha  spinulosa,  M.  and  T.; 
Ophiocten   sericeum,    Forbes  ;     Ophioglypha    sarsii, 
LtJTK. ;    Asteronyx  loveni,  M.  and  T. ;    and  Astero- 


44  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

jjhyton  linckli,  M.  and  T  ,  from  Mr.  Gwyn  Jeffreys' 
dredgings  in  1870.  Deep-sea  forms  dredged  round 
our  coast  identical  with  northern  species  have  been 
usually  regarded  as  '  boreal  outliers '  (Eorbes),  or  at 
all  events  as  species  which  have  extended  their  dis- 
tribution from  northern  centres.  This  idea  probably 
arose  in  a  great  measure  from  their  having  been 
discovered  and  first  described  in  Scandinavia.  We 
actually  know  nothing  about  their  centres  of  distri- 
bution ;  all  ^^Q  know  of  them  is  that  they  are  the  in- 
habitants of  an  enormously  extended  zone  of  special 
thermal  conditions,  which  '  crops  out,'  as  it  were,  or 
rather  comes  within  range  of  the  ordinary  means  of 
observation,  off  the  coasts  of  Scandinavia. 

Edward  Eorbes  pointed  out  long  ago  the  kind  of  in- 
verted analogy  which  exists  between  the  distribution  of 
land  animals  and  plants  and  that  of  the  fauna  and  flora 
of  the  sea.  In  the  case  of  the  land,  while  at  the  level 
of  the  sea  there  is,  in  temperate  and  tropical  regions,  a 
luxuriant  vegetation  with  a  correspondingly  numerous 
fauna,  as  we  ascend  the  slope  of  a  mountain  range 
the  conditions  gradually  become  more  severe  ;  species 
after  species  belonging  to  the  more  fortunate  plains 
beneath  disappear,  and  are  replaced  by  others  whose 
representatives  are  only  to  be  found  on  other  moun- 
tain ridges,  or  on  the  shores  of  an  arctic  sea.  In  the 
ocean,  on  the  other  hand,  there  is  along  the  shore  line 
and  within  the  first  few  fathoms,  a  rich  and  varied 
flora  and  fauna,  which  participates  and  sympathises 
in  all  the  circumstances  of  climate  which  affect  the 
inhabitants  of  the  land.  As  we  descend,  the  condi- 
tions gradually  become  more  rigorous,  the  tempera- 
ture falls,  and  alterations  of  temperature  are  less  felt. 


niAP.  I.]  INTRODUCTION.  45 

The  fauna  becomes  more  uniform  over  a  larger  area, 
and  is  manifestly  one  of  which  the  shallower  water 
fauna  of  some  colder  region  is  to  a  great  extent  a 
lateral  extension.  Going  still  deeper,  the  severity  of 
tlie  cold  increases  until  we  reach  the  vast  undulating' 
plains  and  valleys  at  the  bottom  of  the  sea,  with  their 
fauna  partly  peculiar  and  partly  polar — a  region  the 
extension  of  whose  extreme  thermal  conditions  only 
approaches  the  surface  within  the  arctic  and  antarctic 
circles. 

"We  have  as  yet  very  little  exact  knowledge  as  to 
the  distance  to  which  the  sun's  light  penetrates  into 
the  water  of  the  sea.  According  to  some  recent 
experiments  which  will  be  referred  to  in  a  future 
chapter,  it  would  appear  that  the  rays  capable  of 
aflPecting  a  delicate  photographic  film  are  very  rapidly 
cut  off,  their  effect  being  imperceptible  at  the  depth 
of  only  a  few  fathoms.  It  is  probable  that  some 
portions  of  the  sun's  light  possessing  certain  pro- 
perties may  penetrate  to  a  much  greater  distance,  but 
it  must  be  remembered  that  even  the  clearest  sea-water 
is  more  or  less  tinted  by  suspended  opaque  particles 
and  floating  organisms,  so  that  the  light  has  more 
than  a  pure  saline  solution  to  contend  with.  At  all 
events  it  is  certain  that  beyond  the  first  50  fathoms 
plants  are  barely  represented,  and  after  200  fathoms 
they  are  entirely  absent.  The  question  of  the  mode 
of  nutrition  of  animals  at  great  depths  becomes,  there- 
fore, a  very  singular  one.  The  practical  distinction 
between  plants  and  animals  is,  that  plants  prepare 
the  food  of  animals  by  decomposing  certain  inorganic 
substances  which  animals  cannot  use  as  food,  and 
recombining  their  elements  into  organic  compounds 


46  THE  DEPTHS  OF  THE  SEA.  [chap.  i. 

upon  which  animals  can  feed.  This  process  is,  how- 
ever, so  far  as  we  are  at  present  aware,  constantly 
effected  under  the  influence  of  light.  There  seems 
to  he  little  or  no  light  at  the  hottom  of  the  sea, 
and  there  are  certainly  no  plants  except  such  as 
may  sink  from  the  surface,  hat  the  hottom  of  the 
sea  is  a  mass  of  animal  life.  At  first  sight  it 
certainly  seems  difficult  to  account  for  the  main- 
tenance of  this  vast  animal  population  living  with- 
out any  visible  means  of  support.  Two  explanations 
have  been  suggested.  It  is  conceivable  that  certain 
animal  forms  may  have  the  power  of  decomposing 
water,  carbon  dioxide,  and  ammonia,  and  re-com- 
bining their  elements  into  organic  compounds  without 
the  agency  of  light.  Dr.  "Wallich  supports  this  view, 
and  in  doing  so  he  states  that  "  No  exceptional  law 
is  invoked,  but,  on  the  contrary,  that  the  proof  of 
these  organisms  being  endowed  with  the  power  to 
convert  inorganic  elements  for  their  own  nutrition 
rests  on  the  undisputed  power  which  they  possess 
of  separating  carbonate  of  lime  or  silica  from  waters 
holding  these  substances  in  solution."  ^  This,  how- 
ever, seems  scarcely  satisfactory.  All  the  substances 
employed  in  the  nutrition  of  animals  are  offered  to 
them  finally  in  solution  in  water,  and  the  abstraction 
of  these  from  their  watery  solutions  cannot  be  re- 
garded as  a  'chemical  separation.'  The  broad  dis- 
tinction still  remains,  that  when  carbon  dioxide  in 
solution  is  presented  to  a  green  plant  in  the  sun- 
shine it  can  decompose  it,  while  an  animal  cannot. 

I  believe   we   have   a   simpler    explanation.      All 
sea- water    contains   a   certain    quantity  of   organic 

^  North  Atlantic  Sea-bed,  p.  131. 


CHAP.  1.]  INTRODUCTION.  47 

matter,  in  solution  and  in  suspension.  Its  sources 
are  obvious.  All  rivers  contain  a  considerable  quan- 
tity. Every  shore  is  surrounded  by  a  fringe  which 
averages  a  mile  in  width,  of  olive  and  red  sea- 
weed. In  the  middle  of  the  Atlantic  there  is  a 
marine  prairie,  the  '  Sargasso  sea,'  extending  over 
three  millions  of  square  miles.  The  sea  is  full  of 
animals,  which  are  constantly  dying  and  decay- 
ing. The  amount  of  organic  matter  derived  from 
these  and  other  sources  by  the  water  of  the  ocean 
is  very  appreciable.  Careful  analyses  of  the  water 
were  made  during  the  several  cruises  of  the  '  Porcu- 
pine '  to  detect  it  and  to  determine  its  amount, 
and  the  quantity  everywhere  was  capable  of  being 
rendered  manifest  and  estimated,  and  the  propor- 
tion was  found  to  be  very  uniform  in  all  localities 
and  at  all  depths.  !N'early  all  the  animals  at  extreme 
depths — practically  all  the  animals,  for  the  small  num- 
ber of  higher  forms  feed  upon  these — belong  to  one 
sub-kingdom,  the  Protozoa ;  whose  distinctive  charac- 
ter is  that  they  have  no  special  organs  of  nutrition, 
but  absorb  nourishment  through  the  whole  surface 
of  their  jelly-like  bodies.  Most  of  these  animals 
secrete  exquisitely  formed  skeletons,  some  of  silica, 
some  of  carbonate  of  lime.  There  is  no  doubt  that 
they  extract  both  these  substances  from  the  sea- 
water;  and  it  seems  more  than  probable  that  the 
organic  matter  which  forms  their  soft  parts  is 
derived  from  the  same  source.  It  is  thus  quite 
intelligible  that  a  world  of  animals  may  live  in 
these  dark  abysses,  but  it  is  a  necessary  condition 
that  they  must  chiefly  belong  to  a  class  capable  of 
being  supported  by  absorption  through  the  surface 


48 


THE  DEPTHS  OF  THE  SEA. 


[chap.  I. 


of  their  bodies  of  matter  in  solution,  developing 
but  little  heat,  and  incurring  a  very  small  amount 
of  waste  by  any  manifestation  of  vital  activity. 
According  to  this  view  it  seems  probable  that  at 
all  periods  of  the  earth's  history  some  form  of 
the  Protozoa — rhizopods,  sponges,  or  both — predomi- 
nated greatly  over  all  other  forms  of  animal  life 
in  the  depths  of  the  warmer  regions  of  the  sea. 
The  rhizopods,  like  the  corals  of  a  shallower  zone, 
form  huge  accumulations  of  carbonate  of  lime,  and  it 
is  probably  to  their  agency  that  we  must  refer  most 
of  those  great  bands  of  limestone  which  have  resisted 
time  and  change,  and  come  in  here  and  there  witli 
their  rich  imbedded  lettering  to  mark  like  milestones 
the  progress  of  the  passing  ages. 


TINDHOLM. 


CHAPTER   II. 

! 

THE    CRUISE    OF   THE    '  LIGHTNING.' 

!  I  Proposal  to  investigate  the  Conditions  of  the  Bottom  of  the  Sea. — 
Suggestions  and  Anticipations.  —  Correspondence  between  the 
Council  of  the  Royal  Society  and  the  Admiralty. — Departure 
from  Stornoway. — The  Fseroe  Islands. — Singular  Temperature 
Results  in  the  Faeroe  Channel. — Life  abundant  at  all  Depths. — 
Brisinga  coronata. — HoUenia  carpenteri. — General  Results  of  the 
Expedition. 

J  jAppendix  A, — Particulars  of  Depth,  Temperature,  and  Position  at 
the  various  Dredging  Stations  of  H.M.S.  '  Lightning,'  in  the 
Summer  of  1868;  the  Temperatures  corrected  for  Pressure. 

%*  The  bracketed  numbers  to  the  woodcuts  in  this  chapter  refer  to  the  dredging 
stations  on  Plate  I. 

In  the  spring  of  the  year  1868,  my  friend  Dr.  W. 

B.  Carpenter,  at  that  time  one  of  the  Yice-Presidents 

3f  the  Eoyal  Society,  was  with  me  in  Ireland,  where 

WQ  were   working   out   together   the   structure   and 

levelopment  of  the  Crinoids.     I  had  long  previously 

lad  a  profound  conviction  that  the  land  of  promise 

J   m  the  naturalist,  the  only  remaining  region  where 

^    here  were  endless  novelties  of  extraordinary  interest 

'eady  to  the  hand  which  had  the  means  of  gathering 

hem,  was  the  bottom  of  the  deep  sea.     I  had  even 

lad  a  glimpse  of  some  of  these  treasures,  for  I  had 

een  the  year  before,  with  Professor  Sars,  the  forms 

E 


50  THE  DEPTHS  OF  THE  SEA.  [chap.  n. 

which  I  have  already  mentioned  dredged  by  his  son  at 
a  depth  of  300  to  400  fathoms  off  the  Loffoten  islands. 
I  propounded  my  views  to  my  fellow-labourer,  and 
we  discussed  the  subject  many  times  over  our  micro- 
scopes.    I  strongly  urged  Dr.  Carpenter  to  use  his 
influence  at  head-quarters  to  induce  the  Admiralty, 
probably  through  the  Council  of  the  Hoyal  Society, 
to   give  us  the  use  of  a  vessel  properly  fitted  with 
dredging  gear  and  all  necessary  scientific  apparatus, 
that  many  heavy  questions  as  to  the  state  of  things 
in  the  depths  of  the  ocean  which  were  still  in  a  state 
of  uncertainty,  might  be  definitely  settled.     After  full 
consideration,  Dr.  Carpenter  promised  his  hearty  co- 
operation, and  we  agreed  that  I  should  write  to  him 
on  his  return  to  London,  indicating   generally  the 
results  which  I  anticipated,  and  sketching  out  what 
I  conceived  to  be  a  promising  line  of  inquiry.     The 
Council  of  the  Hoyal  Society  warmly  supported  the 
proposal ;   and  I  give  here  in  chronological  order  the 
short  and  eminently  satisfactory  correspondence  which 
led  to  the  Admiralty  placing  at  the  disposal  of  Dr. 
Carpenter  and  myself  the  gunboat  '  Lightning '  under 
the  command  of  Staff- Commander  May,  R  N.,  in  the 
summer  of  1868,  for  a  trial  cruise  to  the  north  of 
Scotland,  and  afterwards  to  the  much  wider  surveys 
inH.M.S.  'Porcupine,'  Captain  Calver,  E.N.,  which 
were  made  with  the  additional  association  of  Mr.  Gwyn 
Jeffreys  in  the  summers  of  the  years  1869  and  1870. 

From  Prof.  Wyville  Thomson,  Belfast,  to  Dr.  Carpenter,  V.P.B.S. 

May  30,  1868. 

My  dear  Carpenter, — When  I  last  saw  you,  I  suggested  how 
very  important  it  would  be  to  the  advancement  of  science  to 


CHAP.  n.J  THE  CRUISE  OF  THE  'lightning:  51 

determine  with  accuracy  the  conditions  and  distribution  of 
Animal  Life  at  great  depths  in  the  ocean ;  I  now  resume  the 
facts  and  considerations  which  lead  me  to  believe  that  researches 
in  this  direction  promise  valuable  results. 

All  recent  observations  tend  to  negative  Ec^ard  Forbes's 
opinion  that  a  zero  of  animal  life  was  to  be  reached  at  a  depth 
of  a  few  hundred  fathoms.  Two  years  ago,  M.  Sars,  Swedish 
Government  Inspector  of  Fisheries,  had  an  opportunity  in  his 
official  capacity  of  dredging  off  the  Loffoten  Islands  at  a  depth 
of  300  fathoms.  I  visited  Norway  shortly  after  his  return,  and 
had  an  opportunity  of  studying  with  his  father,  Prof.  Sars,  some 
of  his  results.  Animal  forms  were  abundant ;  many  of  them 
were  new  to  science ;  and  among  them  was  one  of  surpassing 
interest,  the  small  Crinoid  of  which  you  have  a  specimen,  and 
which  we  at  once  recognized  as  a  degraded  type  of  the  Apio- 
CEINID^,  an  order  hitherto  regarded  as  extinct,  which  attained 
its  maximum  in  the  Pear-encrinites  of  the  Jurassic  period,  and 
whose  latest  representative  hitherto  known  was  the  Boiirguetti- 
fivinus  of  the  Chalk.  Some  years  previously,  M.  Absjornsen, 
dredging  in  200  fathoms  in  the  Hardangerfjord,  procured  several 
examples  of  a  Starfish  {Brisinga)  which  seems  to  find  its  nearest 
illy  in  the  fossil  genus  Protaster.  These  observations  place  it 
ibeyond  a  doubt  that  animal  life  is  abundant  in  the  ocean  at 
depths  varying  from  200  to  300  fathoms,  that  the  forms  at  these 
^reat  depths  differ  greatly  from  those  met  with  in  ordinary 
Iredgings,  and  that,  at  all  events  in  some  cases,  these  animals  are 
ilosely  allied  to,  and  would  seem  to  be  directly  descended  from, 
he  fauna  of  the  early  Tertiaries. 

I  think  the  latter  result  might  almost  have  been  anticipated ; 
nd  probably  further  investigation  will  add  largely  to  this  class 
f  data,  and  will  give  us  an  opportunity  of  testing  our  deter- 
lination  of  the  zoological  position  of  some  fossil  types  by  an 
xamination  of  the  soft  parts  of  their  recent  representatives, 
''he  main  cause  of  the  destruction,  the  migration,  and  the  extreme 
lodification  of  Animal  tjrpes,  appears  to  be  change  of  climate, 
biefly  depending  upon  oscillations  of  the  earth's  crust.  These 
scillations  do  not  appear  to  have  ranged,  in  the  northern  portion 

E  2 


52  THE  DEPTHS  OF  THE  SEA.  [chap.  ii. 

of  the  Northern  Hemisphere,  much  beyond  1,000  feet  since  the 
commencement  of  the  Tertiary  epoch.  The  temperature  of  deep 
water  seems  to  be  constant  for  all  latitudes  at  39° ;  so  that  an 
immense  area  of  the  North  Atlantic  must  have  had  its  conditions 
unaffected  by  tertiary  or  Post-tertiary  oscillations. 

One  or  two  other  questions  of  the  highest  scientific  interest 
are  to  be  solved  by  the  proposed  investigations  : — 

1st.  The  effect  of  pressure  upon  animal  life  at  great  depths. 
There  is  great  misapprehension  on  this  point.  Probably  a  per- 
fectly equal  pressure  to  any  amount  would  have  little  or  no 
effect.  Air  being  highly  compressible,  and  water  compressible 
only  to  a  very  slight  degree,  it  is  probable  that  under  a  pressure 
of  200  atmospheres,  water  may  be  even  more  aerated,  and  in 
that  respect  more  capable  of  supporting  life,  than  at  the  surface. 

2nd.  The  effect  of  the  great  diminution  of  the  stimulus  of 
Light.  Prom  the  condition  of  the  Cave  Fauna,  this  latter  agent 
probably  affects  only  the  development  of  colour  and  of  the 
organs  of  sight. 

I  have  little  doubt  that  it  is  quite  practicable,  with  a  small 
heavy  dredge,  and  a  couple  of  miles  of  stout  Manilla  rope,  to 
dredge  at  a  depth  of  1,000  fathoms.  Such  an  undertaking 
would,  however,  owing  to  the  distance  and  the  labour  involved,  ; 
be  quite  beyond  the  reach  of  private  enterprise.  What  I  am 
therefore  anxious  for  is,  that  the  Admiralty  may  be  induced, 
perhaps  at  the  instance  of  the  Council  of  the  Eoyal  Society,  to 
send  a  vessel  (such  as  one  of  those  which  accompanied  the  Cable 
Expedition  to  take  soundings)  to  carry  out  the  research.  I  \ 
should  be  ready  to  go  any  time  after  July  ;  and  if  you  would  take 
part  in  the  investigation,  I  cannot  but  believe  that  it  would  give 
good  results. 

I  would  propose  to  start  from  Aberdeen,  and  to  go  first  to  the 
Eockall  fishing-banks,  where  the  depth  is  moderate,  and  thence 
north-westward,  towards  the  coast  of  Greenland,  rather  to  the 
north  of  Cape  Farewell.  We  should  thus  keep  pretty  nearly 
along  the  isotherm  of  39°,  shortly  reaching  1,000  fathoms  depth, 
where, allowing  1,000  feet  for  oscillations  in  level, and  1,000  feet' 
for  influence  of  surface-currents,  summer  heat,  &c.,  we  should 


CHAP.  II. j  THE  CRUISE  OF  THE  '  LIGIJTJSING:  53 

{still  have  4,000  feet  of  water  whose  conditions  have  probably  not 
varied  greatly  since  the  commencement  of  the  Eocene  epoch. 

Yours  most  truly, 

Wyville  Thomson. 


From  Dr.  Carpenter,  V.FM.S.,  to  the  President  of  the  Royal  Society. 

Univehsity  of  Londo]s,  Burlington  House,  \V. 
June  18th,  1868. 

Dear  General  Sabine, — During  a  recent  visit  to  Belfast,  I 
thad  the  opportunity  of  examining  some  of  the  specimens 
retransmitted  by  Prof.  Sars  of  Christiania  to  Prof.  Wyville 
Irhomson)  which  have  been  obtained  by  M.  Sars,  jun..  Inspector 
bf  Fisheries  to  the  Swedish  Government,  by  deep-sea  dredgings 
off  the  coast  of  Norway.  These  specimens,  for  reasons  stated  in 
:he  enclosed  letter  from  Prof.  Wyville  Thomson,  are  of  singular 
j  nterest  alike  to  the  zoologist  and  to  the  palaeontologist ;  and  the 
discovery  of  them  can  scarcely  fail  to  excite,  both  among  natu- 
-alists  and  among  geologists,  a  very  strong  desire  that  the  zoology 
)f  the  deep  sea,  especially  in  the  Northern  Atlantic  region,  should 
oe  more  thoroughly  and  systematically  explored  than  it  has 
ver  yet  been.  From  what  I  know  of  your  own  early  labours  in 
jhis  field,  I  cannot  entertain  a  doubt  of  your  full  concurrence  in 
I  his  desire. 

Such  an  exploration  cannot  be  undertaken  by  private  indi- 
dduals,  even  when  aided  by  grants  from  Scientific  Societies. 
Tor  dredging  at  great  depths,  a  vessel  of  considerable  size  is 
equisite,  with  a  trained  crew,  such  as  is  only  to  be  found  in  the 
xovernment  service.  It  was  by  the  aid  of  such  an  equipment, 
urnished  by  the  Swedish  Government,  that  the  researches  of 
d.  Sars  were  carried  on. 
Now,  as  there  are  understood  to  be  at  the  present  time  an 
nusual  number  of  gun-boats  and  other  cruisers  on  our  northern 
nd  western  coasts,  which  will  probably  remain  on  their  stations 
ntil  the  end  of  the  season,  it  has  occurred  to  Prof.  Wyville 
'homson  and  myself,  that  the  Admiralty,  if  moved  thereto  by 
lie  Council  of  the  Eoyal  Society,  might  be  induced  to  place  one 
t'  these  vessels  at  the  disposal  of  ourselves  and  of  any  other 


54  THE  DEPTHS  OF  THE  SEA.  [chap.  i^. 

naturalists  who  might  be  willing  to  accompany  us,  for  the 
purpose  of  carrying  on  a  systematic  course  of  deep-sea  dredging 
for  a  month  or  six  weeks  of  the  present  summer,  commencing 
early  in  August.  Ml 

Ttiough  we  desire  that  this  inquiry  should  be  extended  bot^B' 
in  geographical  range  and  in  depth  as  far  as  is  proposed  in  Prof 
Wyville  Thomson's  letter,  we  think  it  preferable  to  limit  our- 
selves on  the  present  occasion  to  a  request  which  will  not,  we 
believe,  involve  the  extra  expense  of  sending  out  a  coaling- 
vessel.  We  should  propose  to  make  Kirkwall  or  Lerwick  our 
port  of  departure,  to  explore  the  sea-bottom  between  the  Shetland 
and  the  Fseroe  Islands,  dredging  around  the  shores  and  in  the 
fiords  of  the  latter  (which  have  not  yet,  we  believe,  been 
scientifically  examined),  and  then  to  proceed  as  far  north-west 
into  the  deep  water  between  the  Fseroe  Islands  and  Iceland  as 
may  be  found  practicable. 

It  would  be  desirable  that  the  vessel  provided  for  such 
a  service  should  be  one  capable  of  making  way  under  canvas 
as  well  as  by  steam-power ;  but  as  our  operations  must  neces- 
sarily be  slow,  speed  would  not  be  required.  Considerable  * 
labour  would  be  spared  to  the  crew  if  the  vessel  be  provided  * 
with  a  'donkey-engine'  that  could  be  used  for  pulling  up  the 
dredge.  \ 

If  the  Council  of  the  Eoyal  Society  should  deem  it  expedient  j 
to  prefer  this  request  to  the  Admiralty,  I  trust  that  they  may  i* 
further  be  willing  to  place  at  the  disposal  of  Prof.  WyviUe  \ 
Thomson  and  myself,  either  from  the  Donation  Fund  or  the  i 
Government-Grant  Fund,  a  sum  of  £100  for  the  expenses  we  \ 
must  incur  in  providing  an  ample  supply  of  spirit  and  of  jars  ! 
for  the  preservation  of  specimens,  with  other  scientific  appliances,  f' 
We  would  undertake  that  the  choicest  of  such  specimens  should 
be  deposited  in  the  British  Museum. 

I  shall  be  obliged  by  your  bringing  this  subject  before  the 
Council  of  the  Koyal  Society,  and  remain. 

Dear  General  Sabine,  yours  faithfuUy, 

William  B.  Caepenter. 

The  President  of  the  Royal  Society. 


CHAP.  11.]  TUE  CRUISE  OF  THE  'LIGHTNING:  55 


From  tlic  Minutes  of  the  Council  of  the  Royal  Society, 
Jime  18,  1868. 

These  letters  having  been  considered,  it  was  resolved, — "  That 
the  proposal  of  Drs.  Carpenter  and  Wyville  Thomson  be  ap- 
proved, and  recommended  to  the  favourable  consideration  of  the 
authorities  of  the  Admiralty ;  and  that  a  sum,  of  not  exceeding 
£100,  be  advanced  from  the  Donation  Fund  to  meet  the  expenses 
referred  to  in  Dr.  Carpenter's  letter." 

The  following  draft  of  a  letter  to  be  written  by  the  Secretary, 
to  the  Secretary  of  the  Admiralty,  was  approved  : — 

My  Lord, — I  am  directed  to  acquaint  you,  for  the  information 
of  the  Lords  Commissioners  of  the  Admiralty,  that  the  President 
and  Council  of  the  Eoyal  Society  have  had  under  their  con- 
sideration a  proposal  by  Dr.  Carpenter,  Vice-President  of  the 
Eoyal  Society,  and  Dr.  Wyville  Thomson,  Professor  of  Natural 
History  in  Queen's  College,  Belfast,  for  conducting  dredging 
operations  at  greater  depths  than  have  heretofore  been  attempted 
in  the  localities  which  they  desire  to  explore — the  main  purpose 
of  such  researches  being  to  obtain  information  as  to  the  ex- 
istence, mode  of  life,  and  zoological  relations  of  marine  animals 
living  at  great  depths,  with  a  view  to  the  solution  of  various 
questions  relating  to  Animal  Life,  and  having  an  important  bear- 
ing on  Geology  and  Palaeontology.  The  objects  of  the  opera- 
tions which  they  wish  to  undertake,  and  the  course  which  they 
would  propose  to  follow,  as  well  as  the  aid  they  desire  to  obtain 
from  the  Admiralty,  are  more  fully  set  forth  in  the  letter  of 
Dr.  Carpenter  to  the  President,  and  that  of  Professor  Thomson, 
copies  of  which  I  herewith  enclose. 

The  President  and  Council  are  of  opinion  that  important 
advantages  may  be  expected  to  accrue  to  science  from  the 
proposed  undertaking ;  accordingly  they  strongly  recommend  it 
to  the  favourable  consideration  of  her  Majesty's  Government, 
and  earnestly  hope  that  the  Lords  Commissioners  of  the 
Admiralty  may  be  disposed  to  grant  the  aid  requested.     In  such 


56  TIIE  DEPTHS  OF  THE  SEA.  [chap. 

case-  the  scientific  appliances  required  would  be  provided  for  froij 
funds  at  the  disposal  of  the  Koyal  Society. 

I  am,  &c., 

W.  Shakpey,  Sec.  Rj 

Lord  H.  Lennox,  M.P.,  Secretary  of  the  Admiralty. 

From  the  Minutes  of  the  Council  of  the  Royal  Society 
for  Oct.  20,  1868. 

Admiralty,  lUh  July,  1868 J 
Sir, — In  reply  to  your  letter  of  the  22nd  ultimo,  submitting" 
a  proposition  from  Dr.  Carpenter  and  Professor  Thomson  to 
investigate,  by  means  of  dredging,  the  bottom  of  the  sea  in 
certain  localities,  with  a  view  to  ascertain  the  existence  and 
zoological  relations  of  marine  animals  at  great  depths, — a  re- 
search which  you  and  the  Council  of  the  Eoyal  Society  strongly 
recommend  in  the  interests  of  science  to  the  favourable  con- 
sideration of  her  Majesty's  Government,  for  aid  in  furtherance 
of  the  undertaking, — I  am  commanded  by  my  Lords  Com- 
missioners of  the  Admiralty  to  acquaint  you  that  they  are 
pleased  to  meet  your  wishes  so  far  as  the  Service  will  admit,  and 
have  given  orders  for  her  Majesty's  steam-vessel  'Lightning'  to 
be  prepared  immediately,  at  Pembroke,  for  the  purpose  of  carry- 
ing out  such  dredging  operations. 

I  am.  Sir, 

Your  obedient  Servant, 

W.   G.   EOMAINE. 

To  the  President  of  the  Royal  Society. 

It  will  be  seen  by  the  letters  from  my  colleague 
and  myself  what  our  ideas  were  at  that  time,  and  what 
our  anticipations  as  to  the  result  of  our  labours.  We 
both  more  than  doubted  the  '  anti-biotic '  view  which 
was  then  very  generally  received,  and  we  expected  to 
be  able  to  trace  a  relationship  between  the  living 
inhabitants  of  the  deep  sea  and  the  fossils  of  some  of 
the  later  geological  formations  which  we  looked  upon 
as   their  direct  and  not  very  remote  ancestors.     We 


:iiAF.  II.]  THE  CRUISE  OF  THE  'LIGHTNING:  57 

had  adopted  the  current  strange  misconception  with 
regard  to  the  distribution  of  ocean  temperature ;  and 
jit  is  perhaps  scarcely  a  valid  excuse  that  the  fallacy 
of  a  universal  and  constant  temperature  of  4°  C. 
below  a  certain  depth  varying  according  to  latitude, 
was  at  the  time  accepted  and  taught  by  nearly  all 
the  leading  authorities  in  Physical  Geography. 

Trom  the  time  that  the  Admiralty  gave  their 
sanction  to  the  use  of  a  Government  vessel  for  the 
investigation,  Dr.  Carpenter's  labours  in  working  out 
all  the  necessary  arrangements  and  preparations  were 
unceasing,  and  to  his  influence  in  the  Council  of  the 
Eoyal  Society,  and  to  the  confidence  placed  in  his 
judgment  by  members  of  the  Government  and  men 
{in  official  positions,  the  success  of  the  undertaking  is 
unquestionably  due. 

The  surveying  ship  *  Lightning'  was  assigned  for 
the  service — a  cranky  little  vessel  enough,  one  which 
.had  the  somewhat  doubtful  title  to  respect  of  being 
[perhaps  the  very  oldest  paddle-steamer  in  her 
Majesty's  navy.  We  had  not  good  times  in  the 
'Lightning.'  She  kept  out  the  water  imperfectly, 
and  as  we  had  deplorable  weather  during  nearly  the 
whole  of  the  six  weeks  we  were  afloat,  we  were  in  con- 
|siderable  discomfort.  The  vessel,  in  fact,  was  scarcely 
j seaworthy,  the  iron  hook  and  screw-jack  fastenings  of 
jthe  rigging  were  worn  with  age,  and  many  of  them 
iwere  carried  away,  and  on  two  occasions  the  ship  ran 
I  some  risk.  Still  the  voyage  was  on  the  whole  almost 
pleasant.  Staff-Commander  May  had  lately  returned 
from  Annesley  Bay,  where  he  had  been  harbour-master 
during  the  Abyssinian  war ;  and  his  intelligence  and 
vivacity,  and  the  cordial  good-fellowship  of  his  officers, 


58  THE  DEPTHS  OF  THE  SEA.  [chap. 


I 


who  heartily  seconded  my  colleague  and  myself  in  o 
work  and  sympathised  with  us  in  our  keen  interes 
in  the  curious  results  of  the  few  trials  at  great  depths 
which  we  had  it  in  our  power  to  make,  made  the 
experience,  a  very  novel  one  to  us,  certainly  as 
tolerable  as  possible. 

The  '  Lightning '  left  Pembroke  on  the  4th  of 
August,  1868,  and  arrived  at  Oban  on  the  evening 
of  the  6th.  At  Oban  Dr.  Carpenter,  his  son  Herbert, 
and  I  joined,  and,  after  having  taken  observations 
for  the  chronometers,  completed  coals  and  water, 
and  being  otherwise  ready,  we  left  Oban  on  the  8th 
of  August,  anchored  on  that  evening  in  Tobermory 
Bay,  and  after  a  gusty  passage  through  the  Mincli 
we  reached  Stornoway  on  the  evening  of  the  9th. 
At  Stornoway  we  were  received  by  Sir  James  and 
Lady  Matheson  with  a  courteous  hospitality  which 
on  many  subsequent  occasions  has  made  us  leave 
their  island  kingdom  with  regret  and  return  to  it 
with  pleasure.  We  took  in  as  much  coal  as  we 
could  carry,  stowing  as  mach  as  was  safe  in  bags 
on  the  deck,  set  up  a  dredging  derrick  over  the 
stern,  took  final  observations,  and  departed  to  the 
northward  on  the  morning  of  the  11th.  We  took  a 
haul  or  two  the  same  afternoon  in  from  60  to  100 
fathoms,  about  15  miles  to  the  north  of  the  Butt  of 
the  Lews,  to  try  our  dredging-tackle  and  donkey- 
engine  and  to  trace  the  limits  of  the  shallow-water 
species.  All  the  appliances  worked  well,  but  the 
dredge  brought  up  few  animal  forms,  and  all  of  them 
well-known  inhabitants  of  the  seas  of  the  Hebrides. 
The  next  day  we  were  met  by  a  breeze  from  the  N.E., 
which  continued  for  three  days  with  such  force  that 


jHAP.  II.]  THE  CRUISE  OF  THE  'LIGHTNING:  59 

we  were  compelled  to  lie-to  under  canvas,  drifting  to 
the  northward  towards  the  edge  of  the  Eseroe  Banks, 
any  attempt  to  dredge  being  out  of  the  question. 
On  the  13th,  during  a  lull,  we  sounded  and  found  no 
bottom  at  450  fathoms  (Station  1,  PI.  I.),  with  a 
minimum  temperature  of  9°-5  C,  the  temperature  of 
the  surface  water  being  12°* 5  C.  This  was  so  high  a 
temperature  for  so  considerable  a  depth  that  we  sus- 
pected some  error  in  the  indications  of  the  thermo- 
meters, three  of  Six's  registering  instruments  of  the 
Hydrographic  OfB.ce  pattern.  Subsequent  observa- 
tions however  in  the  same  locality  showed  us  that 
tlie  temperature  to  the  depth  of  600  to  700  fathoms 
in  that  region  is  the  moderate  temperature  of  the 
northward  current  of  the  gulf  stream. 

The  Pseroe  Banks  are  greatly  frequented  in  the 
fishing  season  by  English  and  foreign  fishing- smacks. 
Of  course  the  principal  object  is  to  prepare  cured  or 
hard-fish,  but  many  of  the  English  vessels  are  welled 
for  the  supply  of  fresh  cod  for  the  London  market. 

A  large  square  tank  occupies  the  middle  of  the 
v^essel,  and  holes  in  the  sides  allow  the  water  to  pass 
freely  through  it.  The  water  in  the  tank  is  thus 
kept  perfectly  fresh  ;  the  best  of  the  cod  are  put  into 
it,  and  they  stand  the  voyage  perfectly.  It  is  curious 
to  see  the  great  creatures  moving  gracefully  about 
in  the  tank  like  gold-fish  in  a  glass  globe.  They  are 
Qo  doubt  '  quite  unaccustomed  to  man,'  and  conse- 
iquently  they  are  tame ;  and  with  their  long  smooth 
mottled  faces,  their  huge  mouths,  and  lidless  un- 
speculative  eyes,  they  are  about  as  unfamiliar  objects 
as  one  can  well  see.  They  seem  rather  to  like  to 
be  scratched,  as  they  are  greatly  infested  by  caligi 


60  THE  DEPTHS  OF  TUE  SEA,  [chap.  ii. 

and  all  kinds  of  suctorial  copepods.  One  of  them  will 
take  a  crab  or  a  large  fusus  or  buccinum  quietly  out 
of  one's  hand,  and  with  a  slight  movement  transfer  it 
down  its  capacious  throat  into  its  stomach,  where  it 
is  very  soon  attacked  and  disintegrated  by  the  power- 
ful gastric  secretions.  In  one  welled  smack  I  visited 
on  one  occasion,  one  of  the  fish  had  met  w^ith  some 
slight  injury  which  spoiled  its  market,  and  it  made 
several  trips  in  the  well  between  London  and  Egeroe 
and  became  quite  a  pet.  The  sailors  said  it  knew 
them.  It  was  mixed  up  with  a  number  of  others  in 
the  tank  when  I  was  on  board,  and  certainly  it  was 
always  the  first  to  come  to  the  top  for  the  chance  of 
a  crab  or  a  bit  of  biscuit,  and  it  rubbed  its  '  head 
and  shoulders  '  against  my  hand  quite  lovingly. 

On  the  15th  and  IGtli  we  dredged  over  the  Eseroe 
Banks  at  a  depth  of  from  200  to  50  fathoms,  the 
bottom  gravel  and  nullipore,  and  the  temperature 
from  8°  to  10°  C.  The  banks  swarm  with  the  com- 
mon brittle  star  Ophiothrix fragilis,  with  the  Norway 
lobster  Nephrons  norvegictis,  large  spider  crabs,  several 
species  of  the  genus  Galathea,  and  many  of  the  genus 
Crangon,  So  ample  a  supply  of  their  favourite  food 
readily  accounts  for  the  abundance  and  excellence  of 
the  cod  and  ling  on  the  banks. 

There  is  some  rough  rocky  ground  on  the  Pseroe 
Banks,  and  notwithstanding  all  possible  care  and  the 
use  of  Hodge's  '  accumulators  '  to  ease  the  strain  on 
the  dredge  ropes,  we  lost  two  of  our  best  dredges  and 
some  hundreds  of  fathoms  of  rope.  On  the  morning 
of  the  l7th  M^e  sighted  Eaeroe,  as  usual  only  getting 
now  and  then  a  glimpse  of  the  islands  of  this  remote 
little  archipelago  by  the  lilting  of  the  curtain  of  mist 


CHAP.  II.]  THE  CRUISE  OF  THE  'LIGHTNING:  61 

which  almost  constantly  envelopes  them.  Towards 
mid-day  the  weather  improved  a  little,  and  as  we 
threaded  among  the  islands  towards  the  little  harhour 
of  Thorshavn  we  greatly  enjoyed  our  first  view  of 
their  fantastic  outlines,  partly  shrouded  in  their  veil 
of  mist ;  their  soft  green  and  brown  colouring  ren- 
dered still  softer  by  the  subdued  sub-arctic  light,  and 
the  streams  and  cascades  embroidering  the  gentle 
slopes  of  the  hills  and  falling  over  the  cliffs  like 
silver  threads  and  tassels. 

The  Pseroe  Islands  are  basaltic ;  terrace  over 
terrace  of  soft  easily  decomposed  anamesite  probably 
of  Miocene  tertiary  age.  This  uniform  structure, 
and  the  absence  of  trees  or  any  prominent  form  of 
vegetation,  gives  a  singular  sameness  of  effect.  The 
scattered  habitations  are  usually  sad-coloured  and 
roofed  with  growing  turf,  so  that  they  are  actually 
invisible  at  a  little  distance.  We  were  greatly  struck 
[sometimes  by  the  difficulty  of  estimating  distance 
I  and  height;  from  the  total  want  of  familiar  objects 
for  comparison  it  was  sometimes  difficult  to  tell, 
passing  among  the  islands  and  looking  at  them 
through  the  moist  transparent  air,  whether  the 
ridge  was  500  feet  high,  or  double  or  four  times  that 
I  height.  The  intermediate  height  is  usually  nearest 
the  truth. 

Thorshavn,  the  capital  of  Paeroe,  is  a  strange  little 
place.  The  land  shelves  down  rather  abruptly  to  a 
little  bay,  round  the  head  of  which  the  town  is  built ; 
and  the  habitations  are  perched  among  the  rocks  on 
such  flat  spaces  as  may  be  found  for  their  reception. 
The  result  is  irregular  and  picturesque ;  and  very 
peculiar,  for  something  like  a  scramble  is  necessary 


62  THE  DEPTHS  OF  THE  SEA.  [chap.  ii. 

to  get  along  some  of  the  principal  *  streets.'  Abov^ 
the  town  a  little  clearing  forms  a  miniature  la^ 
and  garden  gay  with  bright  flowers  in  front  of  th< 
Governor's  house,  a  pretty  wooden  cottage  residenc 
like  a  villa  in  a  suburb  of  one  of  the  Scandinavia 
towns. 

Eaeroe,  with  its  wet  sunless  climate  and  precarious 
crops  of  barley ;  its  turf- thatched  cottages  and  quie< 
little  churches ;  its  glorious  cliffs  and  headlands  and 
picturesque  islets,  the  haunt  of  the  eider-duck  and 
the  puffin;  and  its  hardy,  friendly  islanders,  with  their 
quaint,  simple,  semi-Icelandic  semi-Danish  customs, 
has  been  described  again  and  again.  Eseroe  only  came 
to  us  as  a  pleasant  haven  of  rest  in  the  middle  of  our 
northern  work.  We  paid  it  two  visits  of  a  week  each 
in  successive  years,  and  one  of  the  most  pleasant 
memories  in  the  minds  of  all  of  us  connected  with 
these  expeditions  will  always  be  the  cordial  sympathy 
which  we  received  from  our  friend  M.  Holt  en  the 
Danish  Governor,  and  his  accomplished  wife.  M. 
Holten  received  us  with  the  most  friendly  hospitality, 
and  did  everything  in  his  power  at  all  times  to  render 
us  assistance  and  to  further  our  views.  He  introduced 
us  to  the  leading  inhabitants  of  his  dominion,  and 
during  the  many  pleasant  evenings  which  we  spent 
at  his  residence  we  heard  all  that  we  could  of  the 
economy  of  this  simple  little  community,  perhaps  the 
most  primitive  and  the  most  isolated  in  Europe.  To 
Governor  Holten  I  have  already  had  the  pleasure  of 
dedicating  a  singularly  beautiful  sponge-form  which 
we  discovered  during  our  return  voyage ;  and  to 
Madame  Holten,  to  whose  graceful  pencil  I  am  in- 
debted for  the  vimettes  of  Eaeroe  scenerv  which  so 


CHAP.  II.]  THE  CRUISE  OF  THE  'LIGHTNING:  63 

appropriately  close  these  chapters,  I  now  dedicate 
this  volume,  in  remembrance  of  the  great  kindness 
which  we  invariably  experienced  from  her  and  from 
her  excellent  husband. 

We  lay   in   Thorshavn   harbour   till   the  26th  of 
August,  the  weather  being  so  bad  as  to  make  all  idea 
of  pursuing  our  work  outside  hopeless.    "Whenever  it 
was  possible  we  dredged  in  the  fiords  with  Pseroese 
boats  and  native  boatmen,  and  we  made  the  acquaint- 
ance of  Sysselman  Mtiller,  the  representative  of  Eseroe 
in  the  Danish  Parliament,  who   had   made  himself 
thoroughly  conversant  with  the  mollusca  of  Pseroe, 
and  had  contributed  his  information  to  a  list  published 
in  1867  by  Dr.  O.  A.  L.  Morch.     The  shallow-water 
fauna  seems  to  be  scanty,  as  we  find  frequently  to  be 
.the  case  on  a  bed  of  decomposing  trap.     It  is  of  a 
character  intermediate  between  that  of  Shetland  and 
the  Scandinavian  coast.     The  forms  which  perhaps 
interested  us  most  were  Fusus  despectus,  L. — a  hand- 
some shell  which  may  possibly  be  only  a  very  marked 
variety  of  Fusus  anliquiis,  L. ;  but  if  so,  it  is  one  with 
very  definite  limit  of  distribution,  as  it  occurs  only 
rarely  in  very  deep  water  in  the  British  seas.    In  water 
of  moderate  depth  among  the  Pseroes  it  is  abundant, 
apparently  replacing  F.  antiquus.     Another  common 
Faeroe  shell  is  Tellina  calcarea,  Chemnitz, — a  very 
abundant  British  glacial  clay  fossil,  but  not  hitherto 
j found  recent  in  the  British  area.    In  the  glacial  clays 
jaear  Eothesay  it  is  in  regular  beds  associated  with 
Mya  truncata,  L ,  var.  uddevallensis,  Porbes  ;  Saxi- 
oava  norvegica,  Sphengleu;  Fecten  islcmdicus,  O.  P. 
MuLLER,  and  other  northern  forms,  and  frequently 
so  fresh  that  the  two  valves  are  still  in  position  and 


^ 


64  THE  DEPTHS  OF  THE  SEA,  [chap.  n. 

held  together  hy  their  connecting  ligament.    A  some-  ^ 
what  peculiar  variety  of  Uchinus  sphcera,  O.E.Muller,  ! 
was  met  with  in  one  of  the  Pjords  associated  with  a 
large  form  of  U.Jlemingii,  Ball  ;  and  what  appears  to 
be  a  small  form  of  Cuciimaria  frondosa,  Gunner,  was 
very  common  in  shallow  water  on  the  tangles.  [ 

While  we  were  lying  in  Thorshavn  harbour  the  | 
Danish  gunboat  '  Pylla '  and  the  Erench  steam  trans- 1 
port  '  L' Orient '  came  in  on  their  way  from  Iceland. 
Both  of  the  vessels  from  the  north  had  come  through  , 
bad  weather,  and  were  glad  to  run  into  shelter.  During  ■ 
the  stay  of  the  three  war- ships  the  little  capital  was 
quite  gay,  and  the  Governor  had  abundant  opportunity 
of  exercising  his  genial  hospitality.     On  the  26th  of 
August,    as  the  barometer  rose  a  little   and   there  - 
seemed  to  be  some  slight  sign  of  improvement,  we  \ 
left  Thorshavn  and  steamed  southward  to  dredge  if? 
possible  in  the  deep  channel  between  Eseroe  and  Shet-  j 
land ;  but  the  same  evening  wild  weather  set  in  again  ' 
with  a  strong  gale  of  wind  from  the  north-westward, 
and  the   barometer  down  to  29*08.     The  hook  and  i 
screw-jack  fastenings  of  the  main  rigging  went  one! 
after  another,  and  we  narrowly  escaped  losing  thei 
mast.     The  gale  lasted  till  the  29th,  when  there  was 
rather  better  weather ;  and  after  lying-to  and  drifting 
to  the  north-east  for  nearly  three  days,  we  took  a 
sounding  in  lat.  60°  45'  N.,  long.  4°  W  W.  (Station  6). 
This  gave  a  depth  of  510  fathoms  and  a  bottom  tern-  \ 
perature  of  0°  0.     On  the  evening  of  the  29th  and  ■ 
on  the  30th  the  weather  was  sufficiently  moderate  to 
allow   us  to  work  our  dredging  gear,  and  the  first 
trials  were  of  great  interest,  as  it  was  our  first  oppor- 
tunity of  making  the  attempt  in  so  great  a  depth  of 


CHAP,  ir.]  THE  CRUISE  OF  THE  '  lightning:  05 

water.  The  operation  seemed  however  to  present  no 
1  special  difficulty,  and  nearly  every  haul  was  success- 
I  ful.  The  bottom  was  sand  and  gravel,  mostly  derived 
I  from  the  disintegration  of  the  old  rocks  of  the  Scottish 
1  plateau.  Animal  life  was  not  abundant,  but  several 
groups  were  fairly  represented.  Sandy  rhizopods  of  a 
ii  large  size  were  numerous,  and  there  were  several  con- 
I  spicuous  crustaceans  and  echinoderms,  among  the  latter 
;  an  example  of  Astropecien  tenuispijius,  of  a  brilliant 
^  scarlet  colour,  which  came  up  entangled  on  the  line. 

On  the  31st  bad  weather  set  in  again,  and  we  could 

neither  sound  nor  dredge.     On  the  1st  of  September 

we  got  one  temperature  sounding  in  550  fathoms  with 

-  r-2  C,  but  could  do  no  work. 

The  next  day,  September  2,  was  more  moderate, 

land  we  dredged  all  day  at  a  depth  of  only  170  fathoms 

lover  a  very  restricted  shoal,  which,  singularly  enough, 

we  could  not  find  when  we  sought  for  it  the  year 

I  after  in  the   *  Porcupine.'      Here  we  found   animal 

I  life  abundant  and  varied — a  mixture  of  Celtic  and 

I  Scandinavian  forms.      The  bottom  was  chiefly  small 

'rounded  pebbles  of  the  dark  anamesite  of  the  Faeroes, 

and  sticking  to  them,  singly  or  in  little  groups  like 

•plums   on  their  stems,  were  many  large    specimens 

|of  the  rare  brachiopod   Terehratida   cranium,  O.  E. 

'  MtJLLER,  along  with  abundance  of  the  commoner  form 

Terehratulina  caput-serpentis,  L. 

The  following  day,  September  3,  we  were  again  in 
deep  water,  about  500  fathoms,  with  a  bottom  tem- 
perature a  little  below  the  freezing-point,  the  tliermo- 
meter  at  the  surface  giving  10"* 5  C.  Here  we  took 
representatives  of  many  invertebrate  groups — rhizo- 
pods, sponges,  echinoderms,  crustaceans,  and  molluscs; 


QQ  THE  DEPTHS  OF  THE  SEJ.  [chap.  ii. 

among  them  a  magnificent  specimen  of  a  new  star- 
fish A¥hich  has  been  since  described  by  M.  G.  O.  Sars 
under  the  name  of  BrisiHga  coronata  (Fig.  5).  The 
genus  Brislnga  was  discovered  in  1853  by  M.  P.  Chr. 
Absjornsen,  who  then  dredged  several  specimens  of 
another  species,  B.  endecacnemos,  Absj.,  at  a  depth 
of  100  to  200  fathoms  in  the  Ilardangerfjord  on 
the  Norway  coast  a  little  to  the  south  of  Bergen. 
These  are  certainly  very  wonderful  creatures.  At 
first  sight  they  look  intermediate  between  ophiurids 
and  star-fishes,  the  arms  too  thick  and  soft  for  the 
former,  but  much  more  long  and  delicate  than  we 
usually  find  them  in  the  latter  group. 

The  disk  is  small,  about  20  to  25  mm.  in  diameter ; 
in  B,  endecacnemos  nearly  smooth,  in  B.  coronata 
covered  with  spines.     The  madreporiform  tubercle  is 
on  the  dorsal  surface  close  to  the  edge  of  the  disk.    A 
firm  ring  of  calcareous  ossicles  forms  and  supports  the  j 
edge  of  the  disk,  and  gives  attachment  to  the  arms. 
The  arms  are  ten  or  eleven  in  number :  the  latter 
number  is  probably  abnormal.     They  are  sometimes 
as  much  as  30  centimetres  in  length :  narrow  at  the 
base,  where  they  are  inserted  into  the  ring ;  enlarging 
considerably  towards  the  middle,  where  the  ovaries  are  \ 
developed ;  and  tapering  again  to  the  end.     Rows  of  ■ 
long  spines  border  the  ambulacral  grooves  ;  the  spines 
are  covered  with  a  soft  skin,  which,  when  the  animal  is  | 
quite  fresh,  forms  a  little  transparent,  sack-like  expan- 
sion full  of  fluid  at  the  end  of  each  spine.     The  soft 
covering  of  the  spines  is  full  of  small  pedicellarise, 
and  pedicellarise  are  likewise  scattered  in  groups  over 
the  surface  of  the  arms  and  disk. 

The  arms  in  B.  endecacnemos  are  nearly  smooth, 


1'.  II.]  THE  CRUISE  OF  THE  '  LIGHTNING: 


<i7 


Flu.  o.—Brisinga  coromta,  G.  O.  Saks.     >'atunil  size.     (No.  7.) 

F  2 


68  THE  DEPTHS  OF  THE  SEA.  [chap.  ir. 

ribbed  transversely  here  and  there  by  slightly  raised 
calcareous  bands  passing  irregularly  partly  or  wholly 
across  them.     In  B.  coronata  these  ridges  are  sur- 
mounted  by   crests  of   spines.     Both  species  are  of  i 
a  rich  crimson   colour,    passing  into  orange-scarlet.  | 
The   arms   are  easily  detached  from  the  disk.     We 
never  got  one  of  either  species  nearly  entire,  but  even 
coming   up   in  pieces  they  were  certainly  the  most  ; 
striking  objects  we  met  with.     One  was  sufficient  to  i 
give  a  glorious  dash  of  colour  to  a  whole  dredgeful.  \ 
"Le    nom   Brisinga   est   derive    d'un   bijou  brillant  | 
(Brising)  de  la  deesse  Prey  a,"  which  brings  a  pleasant  j 
flavour  of  Scandinavian  heathendom  about  it.     "  J'ai  \ 
trouve  cefcte  Asterie  brillante  a  Hardangerfjord  a  Taide 
du  dredge  a  la  fin  du  mois  d'aout  1853,  a  la  profon- 
deur  de  100  a  200  brasses,  ou  elle  etait  placee  sur  le 
plan  lateral  et  perpendiculaire  d'une  montagne,  qui 
semblait   descendre   de  80  a  90  brasses  jusqu'a  200 
brasses  et  meme  de  plus.     Elle  se  trouve  bien  rare- 
ment ;  en  draguant  plus  de  huit  jours  avec  beaucoup[ 
d'assiduite  dans  la  meme  localite  et  dans  les  environs 
je  trouvais  seulement  quelques  bras,  et  quelques  indi- 
vidus  plus  ou  moins  grands,  dont  le  plus  petit  entre 
les  pointes  des  bras  opposes  avait  une  grandeur  de  6| 
pouces,  le  plus  grand  environ  2  pieds  de  diametre.j 
Aucun  d'eux  n'etait  sans  etre   endommao^e ;  Tanimali 
est  extremement  fragile  et  semble,  comme  les  coma-j 
tules  et  quelques  esp^ces  d'Ophiolepis  et  d'OphiotrixJ 
a  cause  de  la  pression  diminuante  de  I'eau,  tire  vers 
la  surface,  par  un  effort  vigoureux,  se  defaire  de  cesj 
bras,  qui  toujours  se  detachent  a  I'endroit  ou  ils  sonij 
unis  avec  I'anneau  du  disque.     Le  surpois  du  bras  enj- 
comparaison  du  disque  tr^s  petit,  et  la  grandeur  con- 


CHAP.  II.]  THE  CRUISE  OF  THE  'LIGHTNING.'  69 

siderable  de  ranimal,  augmente  aussi  les  difficultes  a 
le  faire  sortir  du  dredge  sans  etre  dechire.  Quoique 
je  fusse  assez  heureux  pour  le  saisir  avant  qu'il  sortait 
de  Teau,  et  malgre  toute  la  precaution  possible,  je 
r^ussis  settlement  a  eonserver  deux  disques  d'une  paire 
de  bras  fermes,  mais  a  ceux-ci  meme  le  peau  etait 
rompue.  Quand  I'animal  est  complet  et  coherent, 
ainsi  que  je  I'ai  vu  une  ou  deux  fois  sous  I'eau  dans 
le  dredge,  il  est  veritablement  un  exemplaire  de  luxe, 
une  '  gloria  maris.'  "^ 

The  bad  weather  was  unrelenting,  and  again  inter- 
rupted us  for  a  couple  of  days  :  we  got  a  sounding 
however  on  the  5th  of  September,  in  lat.  60°  30'  N. 
and  long.  T  16'  W.,  with  no  bottom  at  450  fathoms 
and  a  minimum  temperature  about  the  freezing-point. 
It  will  be  seen  by  the  chart  that  the  last  five  stations, 
Nos.  7  to  11,  form  an  oblique  line  from  south-east  to 
!  north-west  between  the  northern  part  of  Orkney  and 
I  the  FaBroe  Bank.    The  bottom  is  throughout  a  mixture 
I  of  gravel  and  sand,  with  patches  of  mud ;  Nos.  7  and  8 
j  principally  the  debris  of  the  metamorphic  rocks  of 
I  the  north  of  Scotland ;  Nos.   9,  10,   and  11  chiefly 
\  volcanic,  the  detritus  of  the  F^roe  traps.     This  line 
I  of  soundings  is  entirely  within  what  we  afterwards 
learned  to  call  the  '  coM  area,'  the  thermometer  for 
depths  below  300  fathoms  indicating  a  temperature 
slightly  above  or  below  0°  C. 

As  we  were  now  again  approaching  the  Fseroe 
fishing-banks,  we  shaped  our  course  southwards,  and 
on  the  morning  of  September  6th  we  sounded  and 

^  Description  d'un  Xoiiveau  Genre  des  Ast^ries,  par  P.  Chr.  Abs- 
jomsen,  in  "Fauna  littoralis  Norvegiee,"  by  Dr.  M.  Sars,  J.  Koran, 
and  D.  C.  Danielssen.     Seconde  Livraison.     Bergen,  ISoG,  p.  90. 


™1 


70  THE  DEPTHS  OF  THE  SEA.  [chap.  ^J 

dredged  in  lat.  59°  3G',  long.  7°  20' (Station  12),  with  a  | 
depth  of  530  fathoms  and  a  'warm  area'  temperature  ! 
of  6°-4  C.  The  dredging  here  was  most  interesting,  j 
The  bottom  was  for  the  first  time  '  Atlantic  ooze/  a 
fine  bluish-grey  tenacious  calcareous  mud^  with  some  I 
sand  and  a  considerable  admixture  of  Glohigerince. 
Imbedded  in  this  mud  there  came  up  an  extraordinary  ; 
number  of  silicious  sponges  of  most  remarkable  and  | 
novel  forms.  Most  of  these  belonged  to  an  order  ^ 
which  had  been  described  by  the  writer  a  couple  of  I 
years  before  as  '  Porifera  vitrea,'  a  tribe  at  that  time  : 
but  little  known,  but  which  have  since  become  very  \ 
familiar  to  us  as  denizens  of  the  abyssal  zone,  i 
Working  from  more  extended  data,  Professor  Oscar  j 
Schmidt  afterwards  defined  the  group  more  exactly  ' 
as  a  familv,  under  the  name  of  HexactlnellidcB — the  i 
term  which  I  shall  here  adopt.  | 

The   relations   and   peculiarities   of   this   singular  j 
group   will  be  fully  discussed  in  a  future  chapter. 
The  most  characteristic  forms  which  we  met  with  on  j 
this   occasion   were   the   beautiful   sea-nests   of   the  \ 
Setubal    shark-fishers,   IloUenia    carpenter i,  Wy.  T.  ' 
(Fig.    6),    and    the   even   more   strange   Hyalonema 
lusitanieitm,  BARiiOZA  de   Bocage,  closely  related  toi 
the  glass-rope  sponges  of  Japan  which  have  so  long! 
perplexed  naturalists  to  determine  their  position  in ' 
the  animal  series,  and  their  relation  to  their  constant 
companion  the  parasitic  Falythoa. 

B-oUenia  carpenter i  is  an  oval  or  sphere  90  to  100 1 
mm.  in  heiglit,  with  one  large  oscular  opening  at  the! 
top  about    30   mm.    in   diameter,    whence  a  simple 
cylindrical  cavity  cupped  at  the  bottom  passes  down 
vertically  into  the  substance  of  the  sponge  to  the 


I  CHAP.  II.] 


/7/A'  CRUISE  OF  THE  '  LIGHTNING. 


depth  of  55    mm.      The   outer  wall  of  the   sponge 


Fro.  fi,  —  HoUenia  cni-ppnffH.  Wyvili.e  Thomson.     Hfilf  the  nattual  size.    (No.  12.) 


consists  of  a  complicated  network   of  the  cross-like 


72  THE  DEPTHS  OF  THE  SEA.  [chap.  i^J 

heads    of    five-rayed    spicules.       One    ray    of    eacli 
spicule    dips  directly  into  the  hody  of  the   sponge, 
and  the  other  four,  which  are  at  right  angles  to  it, 
form  a  cross  on  the  surface,   giving  it  a   beautiful  ! 
stellate  appearance.     The  silicious  rays  of  one  star 
curve  towards  and  meet  the  rays  of  the  neighbouring 
stars,  and  run  parallel  with  them.     All  the  rays  of  \ 
all  the  spicules  are  thickly  invested  Avith  consistent  f 
semi-transparent  gelatinous  matter,  which  binds  their 
concurrent   branches   together   by  an  elastic  union, 
and  fills  up  the  angles  of  the  meshes  with   softly  \ 
curved   viscous   masses.     This   arrangement    of    the  ^ 
spicules,   free   and   yet   adhering   together   by    long 
elastic  connections,  produces  a  strong,  flexible,  and  j 
very  extensible  tissue.     The  cylindrical  oscular  cavity  | 
within  the  sponge  is  lined  with  nearly  the  same  kind  \ 
of  network. 

When  the  sponge  is  living,  the  interstices  of  the  ! 
silicious  network  are  filled  up  both  outside  and  in  with  \ 
a  delicate  fenestrated  membrane  formed  of  a  glairy  ! 
substance  like  white  of  e^^,  which  is  constantly  \ 
moving,  extending  or  contracting  the  fenestrae,  and  \ 
gliding  over  the  surface  of  the  spicules.  This  | 
'  sarcode,'  which  is  the  living  flesh  of  the  sponge,  \ 
contains  distributed  through  it  an  infinite  number  j 
of  very  minute  spicules,  presenting  the  most  sin-  ] 
gular  and  elegant  forms  very  characteristic  of  each! 
species  of  sponge.  A  constant  current  of  water 
carried  along  by  the  action  of  cilia  passes  in  by: 
apertures  in  the  outer  wall,  courses  through  thej 
passages  in  the  loose  texture  of  the  intermediate  I 
sponge-substance  carrying  organic  matter  in  solution 
and  particles  of  nourishment  into  all  its  interstices, 


CHAP.  II.]  THE  CRUISE  OF  THE  'LIGHTNING:  73 

and  finally  passes  out  by  the  large  '  osculum  '  at  the 
top.  Over  the  upper  third  of  the  sponge  a  multitude 
of  radiating  rigid  silicious  spicules  form  a  kind  of 
ornamental  frill,  and  from  the  lower  third  a  perfect 
maze  of  delicate  glassy  filaments,  like  fine  white  hair, 
spread  out  in  all  directions,  penetrating  the  semi-fluid 
mud,  and  supporting  the  sponge  in  its  precarious  bed 
by  increasing  its  surface  indefinitely  while  adding 
but  little  to  its  weight. 

This  is  only  one  of  the  ways  by  which  sponges 
anchor  themselves  in  the  ooze  of  the  deep  sea. 
Syalonema  sends  right  down  through  the  soft 
mud  a  coiled  whisp  of  strong  spicules,  each  as  thick 
as  a  knitting  needle,  which  open  out  into  a  brush 
as  the  bed  gets  firmer,  and  fix  the  sponge  in  its  place 
somewhat  on  the  principle  of  a  screw  pile.  A  very 
singular  sponge  from  deep  water  off  the  Loffoten 
Islands  spreads  into  a  thin  circular  cake,  and  adds 
to  its  surface  by  sending  out  a  flat  border  of  silky 
spicules,  like  a  fringe  of  white  floss- silk  round  a 
little  yellow  mat ;  and  the  lovely  Euplectella,  whose 
beauty  is  imbedded  up  to  its  fretted  lid  in  the  grey 
mud  of  the  seas  of  the  Philippines,  is  supported  by 
a  frill  of  spicules  standing  up  round  it  like  Queen 
Elizabeth's  ruff. 

The  sponges  of  the  deep-water  ooze  are  by  no 
means  confined  to  one  group.  The  Hexactinellidce 
are  perhaps  the  most  abundant,  but  corticate  sponges 
even,  closely  allied  to  those  which  look  so  rigid  when 
fixed  to  stones  in  shallow  water,  send  out  long  anchor- 
ing spicules  and  balance  themselves  in  the  soft  mud 
(Fig.  7) ;  and  off  the  coast  of  Portugal  Mr.  Gwyn 
Jeffreys    dredged    in    1870   several    small    forms   of 


74  THE  DEPTHS  OF  THE  SEA.  [chap.  n. 

the   B.alicliondrid(B^    with    long    supporting    fibrous 
beards. 

Prom  its  appearance  when  brought  up  Iloltenia 
evidently  lives  buried  in  the  mud  to  its  upper  fringe 
of  spicules.    When  freshly  dredged,  it  is  loaded  with 


Fir..  7.  — 7'is»ji/!on,i«  o(/«ric?/o?')nis,  Wyville  Thomson.     Natural  size.     ;Xo.  12.) 

pale  grey  semi-fluid  sarcode,  full  of  Glohigerincp, 
TriloculhKE,  and  other  rhizopods,  and  covered  in  our 
northern  localities  with  the  little  ophiurid  Aniphiura 
ahifssicola ,  Sars,  and  the  exquisitely  delicate  trans- 


CHAP,  n]  THE  CRUISE  OF  THE  '  LIGHTNING:  75 

parent  clam,  Pecten  vitreus,  Chemnitz.  Holtenia 
extends  from  the  Butt  of  the  Lews  to  Gibraltar,  in 
from  500  to  1,000  fathoms.  Mr.  Saville  Kent, 
dredging  in  Mr.  Marshall  Hall's  yacht  'Noma,'  found 
a  singular  variety  off  the  coast  of  Portugal,  which 
from  its  flatter,  more  hemispherical  form,  and  more 
rigid  anchoring  spicules,  probably  inhabits  a  firmer 
medium.* 

As  might  be  expected,  the  Atlantic  ooze  of  this 
station,  rich  in  rhizopods  giving  an  ample  supply  of 
food,  and  with  a  comparatively  mild  climate,  yielded 
many  living  forms  belonging  to  various  orders.  Along 
with  Globigerince  and  other  small  forms  there  were 

1  many  large  rhizopods,  among  them  Rhabdammina 
abyssorum,  Sars,  a  singularly  regular  triradiate  sandy 
form  of  a  bright  orange  colour,  and  very  hard ;  from 
analyses   made   by  Dr.  Williamson   at    the   request 

I  of  Dr.  Carpenter,  its  hardness  is  apparently  owing  to 
the  cement  employed  by  the  animal  in  the  construc- 
tion of  its  case  containing  phosphate  of  iron,  the  only 
instance  of  the  use  of  this  substance  for  such  a 
purpose  of  which  we  are  yet  aware  :  Astrorhiza 
limicola,  Sandahl,  a  large  irregularly -formed  rhizo- 
pod  with  a  soft  test  of  mud  and  sand :  many  large 
CornuspircB  and  TexttilaricB,  and  large  Bi-  and  Tri- 
locidince  and  other  miliolines  :  a  few  zoophytes,  and 
especially  common  the  curious  sea-pen  Ko'pliohelem- 
mon  miilleri,  Sars,   and    the   fine   branching   coral, 

1  On  the  Hexactinellidae,  or  Hexradiate  Spiculed  Silicious  Sponges, 
taken  in  the  '  Noma '  Expedition  off  the  coast  of  Portugal ;  with 
Description  of  New  Species  and  Revision  of  the  Order.  By  W.  Saville 
Kent,  E.L.S.,  F.R.M.S.,  of  the  Geological  Department,  British 
Museum.     (Monthly  Microscopic  Journal,  November  1st,  1870.) 


76  THE  DEPTHS  OF  THE  SEA.  [chap.  ii. 

Lophohelia  prolifera,  Pallas  :  among  Echinoderms 
some  beautiful  varieties  of  Echinus  norvegicus,  D.  and 
K.,  E.  elegans,  D.  and  K.,  Opliiocten  sericeum,  Porbes, 
and  OpJdacantha  spinulosa,  M.  and  T.,  which  seems  to 
be  universal  in  deep  water,  and  the  curious  little 
crinoid  Rhizocrinus  loffotensis,  Saes,  which  will  be 
described  hereafter :  some  remarkable  crustaceans, 
including  as  one  of  the  inost  prominent  a  scarlet 
Munida  with  remarkably  large  brilliant  eyes,  of  the 
colour  and  lustre  of  burnished  copper. 

We  now  proceeded  towards  Stornoway,  which  we 
reached  on  the  9th  of  September,  dredging  on  our 
way  in  shallowing  water,  and  still  meeting  with  in- 
teresting things  such  as  Antedon  celticus,  Bakrett, 
collected  previously  by  Mr.  Gwyn  Jeffreys  on  the 
coast  of  Ross-shire;  abundance  of  'the  pij)er,'  Cidaris 
p>apillata,  Leske,  until  lately  one  of  the  prizes  of  the 
British  collector,  now  known  to  be  perhaps  the 
most  abundant  of  the  larger  living  forms  at  depths 
from  250  to  500  fathoms  in  the  British  seas. 

The  weather  now  looked  more  promising.  I  was 
unfortunately  obliged  to  return  to  my  duties  in 
Dublin ;  but  as  the  results  already  obtained  led  Dr. 
Carpenter  strongly  to  desire  an  opportunity  of 
examining  both  the  temperature  and  the  animal  life 
of  still  deeper  waters,  it  was  thought  by  him  and 
Captain  May  that,  notwithstanding  the  lateness  of  the 
season,  it  would  be  worth  while  to  venture  another 
short  cruise  in  a  westerly  direction,  where  it  Avas 
known  from  previous  soundings  that  the  depth  was 
beyond  1,000  fathoms.  Accordingly,  after  re- fitting, 
an  operation  which  in  some  respects  was  sorely , 
needed,  and  restoring  as  far  as  possible  the  lost  dredg- ! 


CHAP.  1 1.]  THE  CR  VISE  OF  THE  '  LIGHTNING:  7  7 

ing  gear,  the  '  Lightning '  once  more  steamed  out  of 
Stornoway  Harbour  on  the  14th  of  September. 

After  a  fine  run  of  140  miles  in  a  north-westerly 
direction  from  the  Butt  of  the  Lews,  a  sounding  was 
taken   on  the   morning   of  September   15th,  in  lat. 
59°  59',  long.  9°  15^  with  a  bottom  of  Atlantic  ooze, 
,  at  a  depth  of  650  fathoms  (Station  14).    Still  running 
1  north-westward  sixty  miles  further,   another  sound- 
1  ing  was  taken  on  the  18th,  at  570  fathoms,  when  the 
scoop  of  the  sounding  instrument  brought  up  scarcely 
!  anything  but  entire  Glohigerince,  like  the  finest  sago. 
I  Fifty  miles  further,    in  the  same  direction,  bottom 
I  was  found   at  650   fathoms;    but   on    this  occasion 
J  the   sounding-lead    and    three    thermometers    were 
\  unfortunately  lost  in  hauling  up,  so  that  the  tem- 
I  perature  was  not  ascertained.     A  haul  of  the  dredge 
\  was  taken,  however,  at  this  great  depth,  120  fathoms 
!  deeper  than  at  any  of  the  previous  stations,  perfectly 
successfully,  the  dredge  bringing  up  2\  cwt.  of  very 
viscid  greyish  white  mud.      The  mud  was  everywhere 
traversed  by  the  long  glassy  root-fibres  of  anchoring 
sponges,  and  about  50  fathoms  from  the  dredge  there 
were  two  white  tufts  of  such  fibres  sticking  to  the 
'  rope,   no  doubt  pulled  oflF  the  ground,  as  they  en- 
tangled in  their  meshes  some  ophiurids,  some  small 
I  crustaceans,  and  one  or  two  tube-forming   annelids. 
I  In  the  mud  was  a  remarkable  sea-pen,  which  Pro- 
fessor Kolliker,  who  has  undertaken  the  description 
of  such  things  procured  in  our  several  expeditions, 
refers    to  a  new  genus  under  the  name  of  Bathy- 
ptilum     carpenteris    and    some    large    foraminifera. 
;  Dr.  Carpenter  now  stood  due  north,  wishing  to  get 
'  into  the   deep   trough   between    the    Hebrides    and 


78  THE  DEPTHS  OF  THE  SEA.  [chap.  ii. 

Rockall,  and  on  the  morning  of  September  17th 
sounded  at  a  depth  of  620  fathoms,  in  lat.  59°  49', 
long.  12°  36',  with  a  '  warm  area '  temperature. 

The  weather  now  again  broke,  became  too  un- 
favourable for  work,  and  grew  worse  until  the  fore- 
noon of  the  20th,  when  St.  Kilda  was  in  sight  and  it 
was  blowing  a  strong  gale  with  a  heavy  sea.  At  day- 
light on  Monday  the  21st  off  Barra  Head  the  south 
point  of  the  Hebrides,  a  fresh  easterly  wind  blowing 
the  barometer  low  and  appearances  suspicious,  Capt. 
May  did  not  deem  it  advisable  to  stand  to  sea  again. 
He  therefore,  after  consultation  with  Dr.  Carpenter, 
determined  to  conclude  the  work,  proceeded  down  the 
Sound  of  Mull,  and  anchored  at  Oban  on  the  same 
afternoon.  j 

At  Oban  Dr.  Carpenter  and  his  young  son,  who 
had  manfully  borne  no  little  hardship  and  helped  to 
lighten  the  evil  times  to  his  seniors,  went  on  shore 
and  proceeded  southwards  by  land. 

Her  fate  pursued  the  '  Lightning.'     After  lying  a 
couple  of  days  at   Oban,    Captain  May  started  for 
Pembroke  on   the   24th    September.      On  the  25th 
off  the  Calf  of  Man,  the  barometer  having  suddenly  . 
fallen  and  the  wind  and  sea  fast  rising,  he  determined  | 
to  run  for  Holyhead,  when  suddenly,  without  increase 
of  wind  and  in  a  roll  not  heavier  than  usual,  the  whole 
of  the  weather  fore-rigging  went  by  the  straightening 
or  breaking  of  the  iron  hooks  which  held  it.     Luckily 
the  mast  did  not  fall,  and  after  an  hour  spent  in  tem- 
porarily repairing  it  the   '  Lightning '    proceeded  on  - 
her   course    and   anchored    in   the   new   harbour   of 
Holyhead  about  6  p.m.  i 

The  general  results  of  the  '  Lightning '  expedition 


CHAP.  II.]  THE  CRUISE  OF  THE  'LIGHTNING:  79 

were  upon  the  whole  as  satisfactory  as  we  liad  ventured 
to  anticipate.  The  vessel  was  certainly  not  well  suited 
for  the  purpose,  and  the  weather  throughout  the  cruise 
was  very  severe.  During  the  six  weeks  which  elapsed 
between  our  departure  from  Oban  and  our  return  only 
ten  days  were  available  for  dredging  in  the  open  sea, 
and  on  four  of  these  only  we  were  in  water  over  500 
fathoms  deep.  On  our  return  Dr.  Carpenter  submitted 
to  the  Royal  Society  a  preliminary  report  on  the 
general  results  of  the  cruise,  and  these  were  regarded 
by  the  Council  of  the  Society  as  sufficiently  new  and 
valuable  to  justify  a  strong  representation  to  the 
Admiralty  urging  the  importance  of  continuing  an 
investigation  Avhich  had  already,  even  under  unfavour- 
able circumstances,  achieved  a  fair  measure  of  success. 

It  had  been  shown  beyond  question  that  animal 
life  is  varied  and  abundant,  represented  by  all  the 
invertebrate  groups,  at  depths  in  the  ocean  down  to 
650  fathoms  at  least,  notv/ithstanding  the  extra- 
ordinary conditions  to  which  animals  are  there 
exposed. 

It  had  been  determined  that,  instead  of  the  water 

i3f  the  sea  beyond  a  certain  depth  varying  according 

jto  latitude  having  a  uniform  temperature  of  4°  C,  an 

indraught  of  Arctic  water  may  have  at  any  depth 

beyond  the  influence  of  the  direct  rays  of  the  sun  a 

temperature  so  low  as  —  2°  C. ;  or  on  the  other  hand, 

1  warm  current  may  have  at  any  moderate  depth  a 

:emperature  of  6°-5  C.  :  and  it  had  been  shown  that 

^reat  masses  of  water  at  different  temperatures  are 

noving  about,  each  in  its  particular  course ;   main- 

aining  a  remarkable  system  of  oceanic  circulation, 

md  yet  keeping  so  distinct  from  one  another  that 


80 


THE  DEPTHS  OF  THE  SEA. 


[chap.  II. 


an  hour's   sail  may  be   sufficient  to   pass  from  the 
extreme  of  heat  to  the  extreme  of  cold. 

Pinally,  it  had  been  shown  that  a  large  proportion 
of  the  forms  living  at  great  depths  in  the  sea  belong 
to  species  hitherto  unknown,  and  that  thus  a  new 
field  of  boundless  extent  and  great  interest  is  open 
to  the  naturalist.  It  had  been  further  shown  that 
many  of  these  deep-sea  animals  are  specifically  identi- 
cal with  tertiary  fossils  hitherto  believed  to  be  extinct, 
while  others  associate  themselves  with  and  illustrate 
extinct  groups  of  the  fauna  of  more  remote  periods; 
as,  for  example,  the  vitreous  sponges  illustrate  and 
unriddle  the  ventriculites  of  the  chalk. 


THOUSHAVN. 


FIAP.  II.] 


THE  CRUISE  OF  THE  '  LIGHTNING: 


81 


APPENDIX   A. 


'artimlars  of  Depth,  Temperatwe,  and  Position  at  the  various 
Dredging  Stations  of  If. M.S.  '  Lightning!  ^^  i^^  Summer  of 
1868  ;  the  Temperatures  corrected  for  pressure. 


amber 
.  Jtation. 

Depth  in 
Fathom^. 

6 

510 

7 

500 

8 

550 

10 

500 

11 

450 

12 

530   ; 

14 

650 

15 

570 

; 

17 

;  620 ; 

Bottom 
Temperature. 


Surface 
Temperature. 


Position. 


0°-  5  C. 
1  1 
1  -2 
0  •  3 
0-  5 
6  -4 

5  •  8 

6  •  4 
6  -4 


ir 

1  c. ! 

10 

5 

11 

7 

10 

5 

10 

0 

11 

3 

11 

7 

11 

1 

11 

•  1 

60°  45'  N. 
60  7 
60  10 
60  28 
60  30 
59  36 

59  59 

60  38 
59  49 


4°49'W. 
5  21 

5  59 

6  55 

7  16 
7  20 
9  15 

11  7 

12  36 


i 


¥: 


CHAPTER  III. 

THE    CRUISES    OE    THE    '  PORCUPINE.' 

The  Equipment  of  the  Vessel. — The  first  Cruise,  under  the  direction 
of  Mr.  Gwyn  Jeffreys,  off  the  West  Coast  of  Ireland  and  in  the 
Channel  between  Scotland  and  Rockall. — Dredging  carried  down 
to  1,470  fathoms. — Change  of  Arrangements. — Second  Cruise ;  to 
the  Bay  of  Biscay. — Dredging  successful  at  2,435  fathoms. — Third 
Cruise  ;  in  the  Channel  between  Faeroe  and  Shetland. — The  Fauna 

of  the  '  Cold  Area.' 

J 
Appendix  A. — Official  Documents  and  Official  Accounts' of  preliminary^ 
Proceedings  in  connection  with  the  Explorations  in  H.M.  Survey- 
ing-vessel *  Porcupine,'  during  the  Summer  of  1869. 

Appendix  B. — Particulars  of  Depth,  Temperature,  and  Position  at  tlifj 
various  Dredging  Stations  of  H.M.S.  '  Porcupine,'  in  the  Summei; 
of  1869.  ; 


The  bracketed  numbers  to  the  woodcuts  in  this  chapter  refer  to  the  dredging  ■; 


stations  on  Plates  IL,  III.,  and  IV, 


On  the  18th  of  March,  1869,  an  oral  communicatioif 
was  made  by  the  Hydrographer  to  the  Navy  that  th 
Lords  Commissioners  of  the  Admiralty  had  accede< 
to  the  wish  of  the  Council  of  the  Royal  Society,  an^ 
that  H.M.  Surveying-vessel  'Porcupine'  had  bee 
assigned  for  the  service. 

The  equipment  of  the  'Porcupine'  progressed  rapidl 
under  the  direction  of  her  commander.  Captain  Calve:^ 
with  the  careful  superintendence  in  all  matters  bearir 


•  CHAP.  III.]  THE  CRUISES  OF  THE  *  PORCUPINE:  83 

upon  the  efficiency  of  the  scientific  appliances,  of 
Dr.  Carpenter  assisted  by  a  committee  composed 
of  the  officers  and  a  few  of  the  members  of  the  Royal 
Society.  The  *  Porcupine/  though  a  small  vessel,  was 
well  suited  for  the  work  ;  thoroughly  seaworthy,  very 
steady,  and  fitted  up  for  surveying  purposes.  Captain 
Calver  and  his  officers  had  long  been  engaged  in  the 
arduous  and  responsible  duty  of  conducting  the  sur- 
vey of  the  east  coast  of  Britain,  and  were  trained  to 
minute  accuracy  and  thoroughly  versed  in  the  use  of 
instruments  and  in  the  bearings  of  scientific  investi- 
gation. The  crew  were  chiefly  known  and  tried  men, 
Shetlanders  who  had  spent  many  successive  summers 
in  the  '  Porcupine '  under  Captain  Calver' s  command ; 
returning  to  their  homes  in  Shetland  for  the  winter, 
while  the  vessel  was  laid  up  and  the  officers  employed 
in  bringing  up  their  office  work  at  their  head- quarters 
in  Sunderland. 

The   working   of    the   dredge    was    superintended 
throughout  by  Captain  Calv^er,  whose  trained  ability 
very  early  gave  him  so  complete  a  mastery  over  the 
operation  that  he  found  no  difficulty  in  carrying  it 
down  to  depths  at  which   this  kind  of  exploration 
would  have  been  previously  deemed  out  of  the  ques- 
tion.    It  is  impossible  to  speak  too  highly  of  the  skill 
he  displayed,  or  too  warmly  of  the  sympathy  he  showed 
I  in  our  work.     It  is  a  pleasure  to  add  that  the  other 
I  officers  of  the  '  Porcupine,'  Staff-Commander  Inskip, 
I  Mr.  Davidson,  and  Lieutenant  Browning,  most  heartily 
and  zealously  seconded  their  commander  in  promoting 
I  alike  the  scientific  objects  of  the  expedition  and  the 
'  welfare  and  comfort  of  all  who  were  engaged  in  carry- 
ing them  out. 

G  2 


84  THE  DEPTHS  OF  THE  SEA.  [chap.  jii. 

As  it  was  intended  that  the  exploration  in  the 
'  Porcupine  '  in  the  summer  of  1869  should  occupy 
much  more  time,  and  if  possible  be  much  more 
thorough  than  that  in  the  '  Lightning '  the  year 
before,  the  preparations  for  the  '  Porcupine '  expedi- 
tion were  much  more  elaborate  and  comprehensive. 
The  Committee  of  the  Eoyal  Society  were  desirous 
that  various  important  questions  as  to  the  physical 
condition  and  chemical  composition  of  the  water  at 
great  depths  should  be  investigated  ;  and  the  singular 
temperature  results  of  the  former  cruise  ably  discussed 
by  Dr.  Carpenter  in  his  preliminary  report  had  excited 
so  much  curiosity  and  interest  that  their  further  elu- 
cidation was  regarded  as  vieing  in  importance  with 
that  of  the  distribution  and  conditions  of  animal  life. 
It  was  consequently  decided  that  the  naturalists  direct- 
ing the  exj)edition  should  be  accompanied  by  assistants 
trained  in  chemical  and  physical  work,  and  the  chart- 
room  of  the  vessel  was  fitted  up  as  a  temporary 
laboratory,  with  physical  and  chemical  apparatus  and 
microscopes. 

The  vessel  was  available  from  the  beginning  of 
May  to  the  middle  of  September,  and  as  it  was  im- 
possible for  those  who  had  conducted  the  previous 
expedition  to  be  absent  so  long  from  their  public 
duties,  it  was  resolved  to  have  three  separate  cruises ; 
and  Mr.  Gwyn  Jeffreys,  P.R.S.,  whose  co-operation 
was  specially  valuable  from  his  thorough  knowledge 
of  the  species  and  distribution  of  recent  and  fossil 
mollusca,  was  associated  with  Dr.  Carpenter  and 
myself,  and  undertook  the  scientific  charge  of  the 
first  cruise. 

Mr.  Gwyn  Jeffreys  was  accompanied  by   Mr.  W. 


CHAP.  III.]  THE  CRUISES  OF  THE  'PORCUPINE:  85 

Lant  Carpenter,  B.Sc.,  as  chemist  and  physicist ;  and 
(luring  the  first  cruise  they  explored  the  west  coast  of 
Ireland,  the  Porcupine  Bank,  and  the  chano el  between 
Rockall  and  the  coast  of  Scotland.  It  was  originally 
arranged  that  the  second  expedition,  under  the  charge 
of  the  writer  with-  the  assistance  of  Mr.  Hunter, 
M.A.,  P.C.S.,  assistant  in  the  Ohemical  Laboratory  in 
Belfast,  in  the  physical  department,  should  take  up 
the  ground  to  the  north  of  Bockall,  leading  northwards 
to  the  point  where  we  had  left  off  the  year  before ; 
but  subsequently,  for  reasons  which  will  be  explained 
hereafter,  we  altered  our  plan  and  took  the  second 
cruise  in  the  Bay  of  Biscay.  Dr.  Carpenter  took  the 
direction  of  the  last  cruise,  in  which  we  carefully 
worked  over  the  '  Lightning  channel,'  and  checked 
our  previous  observations  ;  Mr.  P.  Herbert  Carpenter, 
our  former  companion  in  the  '  Lightning,'  doing  the 
analyses  of  water,  and  determining  the  amount  and 
composition  of  its  contained  air;  while  I  went  as 
supernumerary  and  made  myself  generally  useful. 

The  special  appliances  and  apparatus  which  were 
prepared  under  Dr.  Carpenter's  superintendence,  after 
much  consultation  among  experts  in  different  depart- 
j  ments,  for  carrying  out  the  various  investigations,  will 
be  described,  each  in  its  place,  when  describing  the 
several  methods  of  investigation  and  their  general 
results. 

Por  the  management  of  the  dredging  operations 
two  assistants  were  appointed  on  the  recommendation 
of  Mr.  Gwyn  Jeffreys, — Mr.  Laughrin,  of  Polj^erro, 
an  old  coast-guard  man  and  an  associate  of  the  Lin- 
naean  Society,  for  dredging  and  sifting ;  and  Mr.  B. 
S.  Dodd,  for  picking  out,  cleaning,  and  storing  the 


86  THE  DEPTHS  OF  THE  SEA.  [chap.  iti. 

specimens   procured.     Both   remained   with   us    the 
whole  summer. 

The  first  cruise  of  the  '  Porcupine  '  under  the  scien- 
tific charge  of  Mr.  Gwyn  Jeffreys  commenced  on  the 
18th  of  May  and  ended  on  the  13th  of  July.  It  ex- 
tended for  a  distance  of  about  450  miles  along  the 
Atlantic  coasts  of  Ireland  and  Scotland,  from  Cape 
Clear  to  Hockall;  and  included  Lough  Swilly  and 
Lough  Eoyle  and  the  North  Channel  to  Belfast. 

The  first  dredgings  were  made  about  40  miles  off 
Valentia,  in  110  fathoms  water  with  a  bottom  of 
mud  and  sand.  The  result  of  this  dredging  gives  a 
fair  idea  of  the  fauna  of  the  100-fathom  line  on  the 
west  coast  of  Ireland.  The  moUusca  are  mostly 
northern  species,  such  as  Necera  rostrata^  Sprengler; 
Verticordla  ahyssicola,  Jeffreys;  Dentalimn  ahys- 
soritm,  Sars  ;  Buccinum  humphreysianiim,  Bennett  ; 
and  Fleurotoma  carinatttm,  Bivona.  Some  however, 
as  Ostrea  cochlear,  PoLi ;  Aporrhals  serresianns, 
Miciiaud;  Murex  lamellosiis,  Cristofori  and  Jan; 
and  Trochiis  gramdatus,  Born, —  are  Mediterranean 
forms,  and  impart  somewhat  of  a  southern  character 
to  the  assemblage.  Cidaris  papillata,  Leske  ;  Echi- 
nus  rarispina,  G.  O.  Sars  ;  U.  elegans,  D.  and  K. ; 
Spatangus  raschi^  Loven  ;  and  several  varieties  of 
CaryopJiyllia  horealis,  Eleming,  were  abundant: 
but  these  species  seem  to  abound  at  a  depth  of  from 
100  to  200  fathoms  from  the  Mediterranean  to  the 
North  Cape. 

After  coaling  at  Galway  they  proceeded  southwards, 
and  as  the  weather  was  very  rough  and  unpromising 
they  dredged  in  shallow  water,  from  20  to  40  fathoms, 
in  Dingle  Bay :  and  the  next  week,  with  improving 


1 


I 


CHAP,  in.]  THE  CRUISES  OF  THE  'PORCUPINE:  87 

weather,  off  Yalentia  and  between  Valentia  and 
Galway,  at  depths  varying  from  80  to  808  fathoms 
(Station  2),  with  a  temperature  at  the  latter  depth  of 
5°-2  C.  The  general  character  of  the  fauna  was  that 
which  we  have  hitherto  been  in  the  habit  of  regarding 
as  Northern.  Several  interesting  things  were  met 
with — Nuciila  timiidiila.  Malm.;  JJedaJrigida, ToubIjI,; 
Verticordia  ahyssicola,  Jeffreys  ;  and  Siphonodenta- 
lium  qumquangtilare,  Forbes.  Among  the  echino- 
derms  a  multitude  of  the  large  form  oi  Echinus  norve- 


¥ia.%.—Gonopl(xxrhcmiboides,¥KB^ic\vs,.     Young.    Twice  the  natural  size.    (No.  3.) 

gicus,  D.  and  K.,  which  I  am  now  inclined  to  regard, 
along  with  several  of  its  allies,  as  a  mere  variety  of 
E.  flemingii,  Ball  ;  and  the  fine  asterid  already 
mentioned,  Brisinga  coronata,  G.  O.  Sars.  Some 
interesting  crustaceans,  including  Gonoplax  rhom- 
boides,  Pab.  (Fig.  8),  a  well-known  Mediterranean 
species,  and  a  young  specimen  of  Geryon  fridens, 
Kroyer  (Fig.  9),  a  rare  Scandinavian  form,  and  the 
only  known  North  European  brachyurous  crustacean 


88  THE  DEPTHS  OF  THE  SEA.  [chap.  hi. 

which  had  not  previously  been  taken  in  the  British 
seas. 

Here  the  Miller-Casella  thermometers  were  tried 
for  the  first  time  and  compared  with  those  of  the 
ordinary  construction.  The  minimum  recorded  by 
one  of  the  former  w^as  5°-2  C,  while  that  recorded  by 
one  of  the  best  ordinary  instruments  of  the  Hydro- 
graphic  Office  pattern  was  7°*3  C.  As  this  difference 
of  2°  C.  was  almost  exactly  what  the  results  of  the  ex- 
periment previously  made  had  indicated  as  the  effect 


Fig.  9. — Geryon  trkhns,Kvt,oy}s.-R.     Young.     Twice  tlie  natural  size.    (No.  7.) 

of  a  pressure  of  1  ton  on  the  square  inch,  which  is 
about  equal  to  the  pressure  of  a  column  of  sea-water 
of  800  fathoms,  this  close  coincidence  gave  great 
confidence  in  the  practical  working  of  the  protected 
instrument,  a  confidence  which  all  subsequent  ex- 
perience has  fully  justified. 

Mr.  Gwyn  Jeffreys  and  his  companions  next  pro- 
ceeded to  examine  the  sea-bed  between  Galway  and 
Porcupine   Bank,  a  shoal  discovered  during  one   of 


CHAP.  III.]  THE  CRUISES  OF  THE  'PORCUPINE:  89 

tlie  previous  cruises  of  our  little  vessel  under  the 
command  of  Lieut.  Hoskyn,  K.N..  The  deepest 
dredging  of  this  excursion  was  1,230  fathoms,  with 
a  minimum  temperature  of  3°'2  Q.,  and  a  bottom  of 
fine  grey  mud  with  a  considerable  admixture  of 
sand.  Animals  were  abundant  even  at  this  great 
depth :  among  the  moUusca  several  new  forms  allied 
to  Area;  Trochus  minutissimus,  Mighel,  a  North 
American  species ;  and  several  others ;  several  crus- 
taceans, and  many  interesting  foraminifera.  As  in 
previous  dredgings  in  deep  water,  the  miliolines  were 
of  very  large  size,  and  the  large  cristellarians  showed 
every  gradation  in  their  axis  of  growth  from  the 
i  rectilineal  to  the  spiral.  In  the  shallower  dredgings 
I  of  this  cruise  the  general  character  of  the  fauna  was 
much  the  same  as  before.  It  had  what  we  have  been 
in  the  habit  of  considering  a  northern  '  facies,'  but 
.probably,  as  already  explained,  because  the  largely 
extended  deep-water  fauna  at  a  temperature  of 
0°  to  +  3°C.,  of  which  it  forms  a  part,  has  hitherto 
only  been  investigated  off  the  coast  of  Scandinavia, 
where  it  crops  up  within  reach  of  observation. 

Limopsis  aurita,  Brocchi;  Area  glacialis,  Gray; 
Vertieordia  abyssieola,  Jepfreys;  Dentalium  ahys- 
Borum,  Sars  ;  Troehus  c'mereus,  Da  Costa  ;  Fusus 
despeetus,  L. ;  F,  islandieus,  Chem.  ;  F.  fenestratus, 
TuRT ;  Columhella  haliceeti,  Jeffreys  ;  Cidaris  papil- 
lata,  Leske  ;  Eehinus  norvegiens,  D.  and  K. ;  and 
Lophohelia  prolifera^  Pallas,  were  found  in  these 
dredgings. 

The  '  Porcupine '  next  put  into  Killibegs  Bay,  on 
the  north  coast  of  Co.  Donegal,  and  coaled  there  for 
her  trip  to  Kockall.     As  it  was  anticipated  that  this 


90  THE  DEPTHS  OF  THE  SEA.  [chap.  hi. 

trip  would  require  a  clear  fortnight,  as  much  coal  was 
stacked  on  deck  as  was  considered  prudent. 

This  cruise  was  entirely  successful.  The  weather 
was  remarkably  fine,  and  Mr.  Gwyn  Jeffreys'  party 
found  it  possible  to  work  the  dredge  during  seven 
days  at  depths  exceeding  1,200  fathoms,  and  on  four 
days  at  less  depths.  The  greatest  depth  achieved  was 
1,476  fathoms  (Station  21),  and  this  dredging  yielded 
moUusca,  a  stalked-eyed  crustacean  with  unusually 
large  eyes,  and  a  fine  specimen  of  Holothuria  tremula. 

The  deep  dredgings  in  this  trip  yielded  an  abund- 
ance of  novel  and  most  interesting  results  in  every 
sub-kingdom  of  the  invertebrates.  Among  the  mol- 
lusca  were  valves  of  an  imperforate  brachiopod,  with 
a  septum  in  the  lower  valve,  which  Mr.  Jeffreys 
proposes  to  name  Atretia  gnomon.  Among  the  Crus- 
tacea were  new  species  of  the  D tasty lidw,  and  many 
forms  of  Isopoda,  Amphipoda,  and  Ostracoda,  several 
of  them  new  to  science. 

Two  or  three  specimens  were  obtained  at  a  depth 
of  1,215  fathoms  (Station  28)  of  a  very  remark- 
able echinoderm  belonging  to  the  genus  Pour- 
talesia,  A.  Ag.  All  these  specimens  were  appa- 
rently immature,  judging  by  tlie  condition  of  the 
ovaries.  I  have  named  this  species  provisionally 
Fourtalesia  phiale.  After  careful  consideration  I 
have  come  to  the  conclusion  that  it  is  not  the 
young  of  a  form  of  which  we  afterwards  took  a 
mature  example  in  the  cold  area  between  Pgeroe  and 
Shetland  (Station  64),  which  will  be  described  here- 
after. Fine  corals  were  constantly  dredged  in  the 
more  moderate  depths,  particularly  great  living  masses 
of  Lophohelia  prolifera  (T'ig.  30),  with  smaller  tufts 


;hap.  in.]  THE  CRUISES  OF  THE  '  PORCUPINE: 


91 


of  AmpMhelia  ramea,   and  everywhere   the    several 
varieties  of  Ca?yophi/llia  horealis. 

The  foraminifera,  as  before,  were  remarkable  for 
their  size,  and  the  same  types  were  predominant ; 
but  species  were  here  obtained  for  the  first  time  of  a 


Fig.  10.— 0/-Z/(7oZi7e.s /8«iu'5si«ii/if;,  Carpenter  MSS.     Magnified.    (No.  28.) 

(peculiarly  interesting  Orbitolite,  a  type  not  hitherto 
liiscovered  farther  north  than  the  Mediterranean, 
i^nd  there  attaining  a  comparatively  small  size. 
[OrbitoUtes  temdssimus,  CAnvB^TE^  MSS.  (Pig.  10), 
IS  Avhen  complete  about  the  size  of  a  sixpence,  and  as 


« 


92  THE  DEPTHS  OF  THE  SEA.  [chap.  iii. 

thin  as  paper.  Erom  its  extreme  tenuity  and  the 
ease  with  which  the  rings  of  chamherlets  of  which 
it  is  composed  separate  from  one  another,  all  our 
large  specimens  were  more  or  less  injured.  All 
the  chamherlets  are  on  the  same  plane ;  this  spe- 
cies therefore  belongs  to  the  *  simple  type  '  of  the 
genus,  though  the  form  of  the  chamherlets  corre- 
sponds, as  Dr.  Carpenter  has  pointed  out,  with  those 
of  the  superficial  layer  in  the  complex  type.  Another 
peculiarity  which  Dr.  Carpenter  regards  as  of  special 
importance  in  its  general  bearings,  is  that,  instead  of 
commencing  with  a  '  central '  and  '  circumambient ' 
chamber  like  the  ordinary  Orhitolites,  this  form  com- 
mences with  a  spine  of  several  turns  like  that  of  a 
young  Cormispira,  thus  showing  the  fundamental 
conformity  of  this  cyclical  type  to  the  spiral  plan  of 
growth.^ 

As  I  have  already  mentioned,  it  was  the  original 
intention  to  devote  the  second  cruise  to  the  exploration 
of  an  area  to  the  west  of  the  outer  Hebrides,  between 
Rockall  and  the  south-western  limit  of  last  year's 
work  in  the  '  Lightning.'  During  the  first  cruise 
however  dredging  had  been  carried  down  successfully 
to  a  depth  of  nearly  1,500  fathoms ;  and  the  result 
so  far  realized  our  anticipations,  and  confirmed  the 
experience  of  last  year.  The  conditions  (to  that 
great  depth  at  all  events)  were  consistent  Avith  the  life 

1  Researches  on  the  Foraminifera.  Part  I.  In  the  Philosophical; 
Transactions  of  the  Royal  Society  of  London  for  the  year  1855 J 
P.  193  et  seq.  I 

Introduction  to  the  Study  of  the  Foraminifera.  By  William  C ! 
Carpenter,  M.D.,  F.R.S.,  F.L.S.,  F.G.S.,  (fcc.  Published  for  the  Rayi 
Society,  1862.     P.  106  et  seq.  \ 


CHAP.  III.]  THE  CRUISES  OF  THE  '  PORCUPINE:  93 

of  all  the  types  of  marine  invertebrata ;  though 
undoubtedly  in  very  deep  water  the  number  of  species 
procured  of  the  higher  groups  was  greatly  reduced, 
and  in  many  cases  the  individuals  appeared  to  be 
dwarfed.  Prom  these  observations  (which  thoroughly 
corroborated  those  of  Dr.  Wallich  and  others,  about 
which  there  had  been  some  difference  of  opinion  on 
account  of  the  imperfection  of  the  appliances  at  the 
command  of  the  observers),  we  concluded  that  prob- 
ably in  no  part  of  the  ocean  were  the  conditions  so 
altered  by  depth  as  to  preclude  the  existence  of 
animal  life,— that  life  had  no  bathy metrical  limit. 
Still  we  could  not  consider  the  question  thoroughly 
settled ;  and  when  upon  consultation  with  Captain 
Calver  we  found  him  perfectly  ready  to  attempt  any 

j  depth,  and  from  his  previous  experience  sanguine  of 
success,  we  determined  to  apply  to  the  Hydrographer 
to  sanction  an  attempt  to  dredge  in  the  deepest  sound- 
ings within  our  reach,  viz.  2,500  fathoms  indicated 
on  the  chart  250  miles  west  of  Usliant.  The  deepest 
reliable  soundings  do  not  go  much  beyond  3,000 
fathoms;  and  we  felt  that  if  we  could  establish  the 
existence  of  life,  and  if  we  could  determine  the 
conditions  with  accuracy  down  to  2,500  fathoms,  the 
general  question  would  be  virtually  solved  for  all 
depths  of  the  ocean,  and  any  further  investigation  of 
its  deeper  abysses  would  be  mere  matter  of  curiosity 

I  and  of  detail.  The  Hydrographer  cordially  acquiesced 
in  this  change  of  plan ;  and  on  the  I7th  of  July  the 
*  Porcupine'  left  Belfast  under  the  scientific  direction 
of  the  writer  ;  Mr.  Hunter,  P.C.S.,  Chemical  Assistant 
in  Queen's  College,  Belfast,  taking  charge  of  the 
examination  and  analysis  of  the  sea-water. 


94  THE  DEATHS  OF  THE  SEA.  [chap.  m. 

The  weather  was  very  settled.  On  the  Sunday,  as 
we  steamed  down  the  Irish  Channel  there  was  nearly 
a  dead  calm,  a  slight  mist  hanging  over  the  water 
and  giving  some  very  beautiful  effects  of  coast 
scenery.  On  the  evening  of  Sunday  the  18th  we 
anchored  for  the  night  off  Bally cottin,  a  pretty  little 
port  about  fifteen  miles  from  Queenstown,  and 
dropped  round  to  Queenstown  on  Monday  morning, 
where  we  anchored  off  Haulbowline  Island  at  7  a.m. 
At  Queenstown  Mr.  P.  Herbert  Carpenter  joined 
Mr.  Hunter  in  the  laboratory,  to  practise  under  his 
direction  the  gas-analysis,  which  it  had  been  arranged 
that  he  should  undertake  during  the  third  cruise. 
Monday  the  18th  was  employed  in  coaling  and  pro- 
curing in  Cork  some  things  which  were  required  for 
the  chemical  department ;  and  at  7  p.m.  we  cast  off 
from  the  wharf  at  Haulbowline  and  proceeded  on  our 
voyage. 

During  Monday  night  we  steamed  in  a  south- 
westerly direction  across  tiie  mouth  of  the  Channel. 
On  Tuesday  we  dredged  in  74  and  75  fathoms  on  the 
plateau  which  extends  between  Cape  Clear  and  Ushant,  ^ 
on  a  bottom  of  mud  and  gravel  with  dead  shells  and 
a  few  living  examples  of  the  generally  diffused  species 
of  moderate  depths.  The  weather  was  remarkably 
fine,  the  barometer  30*25  in.,  and  the  temperature  of 
the  air  22°-5  C. 

On  Wednesday,  July  21,  we  continued  our  south- 
westerly course,  the  chart  indicating  during  the  earlier 
part  of  the  day  that  we  were  still  in  the  shallow 
water  of  the  plateau  of  the  Channel.  At  430  a.m., 
we  dredged  gravel  and  dead  shells  in  95  fathoms,  but; 
toAvards  mid- day  the  lead  gave  a  much  greater  depth ;  | 


niAP.  III.]  THE  CRUISES  OF  THE  *  PORCUPINE:  95 

and  in  the  afternoon,  rapidly  passing  over  the  edge 

of  the  plateau,  we  dredged  in  725  fathoms  with  a 

bottom  of  muddy  sand  (Station  36).     This  is  about 

ithe  bathymetrical    horizon    at   which    we   find   the 

ivitreous  Sponges  in  the  northern  area ;  and  although 

the  bottom  is  here  very  diff*erent,  much  more  sandy 

with  but  a  slight  admixture  of  globigerina  ooze,  we 

iredged  a  specimen,  tolerably  perfect  though  dead, 

)f  Aphrocallistes  hocagei,  Wright,  a  vitreous  sponge 

ately  described  by  Dr.  E.  Perceval  Wright  from  a 

specimen  procured  by  Professor  Barboza  de  Socage 

rom  the  Cape-Yerde  Islands,  and  one  or  two  small 

pecimens  of  SoUenia  carpenteri,  Wy.  T.    The  muddy 

;and  contained  a  considerable  proportion  of  gravel 

i-nd  dead  shells. 

On  Thursday,  July  22,  the  weather  was  still  re- 

jaarkably  fine.     The  sea  was  moderate,  with  a  slight 

well  from  the  north-west.    We  sounded  in  lat.  47°  38' 

f.,  long.   12°  08'   W.,   in  a  depth  of  2,435  fathoms 

Station  37),  when  the  average  of  the  Miller- C  a  sella 

hermometers    gave    a    minimum    temperature    of 

'•5  C. 

As  this  was  about  the  greatest  depth  which  we  had 

3ason  to  expect  in  this  neighbourhood,  we  prepared 

)  take  a  cast  of  the  dredge.     This  operation,  rather 

serious  one  in  such  deep  water,  will  be  described 

I  detail  in  another  chapter.     It  was  perfectly  suc- 

3ssful.     The   dredge-bag  which   was    safely   hauled 

1  deck  at  1  o'clock  on  the  morning  of  the  23rd, 

'ter  an  absence  of  7^  hours  and  a  journey  of  up- 

ards  of  eight  statute  miles,  contained  li  cwt.   of 

iry   characteristic    grey    chalk-mud.      The    dredge 

speared   to   have    dipped    rather    deeply    into    the 


96  THE  DEPTHS  OF  THE  SEA.  [chap.  iii. 

soft  mud,  as  it  contained  amorphous  paste  with  hut 
a  small  proportion  of  fresh  shells  of  GloUgerina 
and  Orbulina.  There  was  an  appreciable  quantity 
of  diffused  amorphous  organic  matter,  which  we 
were  inclined  to  regard  as  connected,  whether  as 
processes,  or  '  mycelium,'  or  germs,  with  the  various 
shelled  and  shell-less  Protozoa,  mixed  very  likely 
with  the  apparently  universally  distributed  moner 
of  deep  water,  Bathyhius, 

On  careful  sifting,  the  ooze  was  found  to  contain 
fresh  examples  of  each  of  the  Invertebrate  sub-king- 
doms. When  examined  at  daylight  on  the  morning 
of  the  23rd  none  of  these  were  actually  living,  but 
their  soft  parts  were  perfectly  fresh,  and  there  waa 
ample  evidence  of  their  having  been  living  when  they 
entered  the  dredge.  The  most  remarkable  species 
were  :  — 

MoLLUSCA. — Dentalium,  sp.  n.,  of  large  size. 

Fecten  fenestratus,   Porbes,    a    Mediterranean 

species. 
Dacrydium  vitreum,  Torell  ;  Arctic,  Norwegian, 

and  Mediterranean. 
Scrobicularia     nitida,      Muller  ;      Norwegian, 

British,  and  Mediterranean. 
Necera  obesa,  Loven  ;  Arctic  and  Norwegian. 
Crustacea. — Anonyx  Iwlbollii,  Kroyer  {==A.  den- 
'     ticulatus,  Bate),  with  the  secondary  appendage 
of  the  upper  antennae  longer  and  more  slender 
than  in  shallow-water  specimens. 
Ampelisca  cequicomis,  Bruzelius. 
Munna,  sp.  n.  > 

One  or  two  Annelides  and  Gephyrea,  which  have 
not  yet  been  determined. 


FiAP.  111.]         THE  CRUISES  OF  THE  'PORCUPINE:  97 

EcHiNODERMATA. — OpMocten    sericetim,    Forbes  ; 
several  well-grown  specimens. 
Echinocucumis  typica,  Saks.     This  seems  to  be  a 
very  widely  distributed  species ;  we  got  it  in 
almost  all  our  deep    dredgings,  both  in   the 
warm  and  in  the  cold  areas. 
A  remarkable  stalked  crinoid  allied  to  Hhizocrimis, 
lit  presenting  some  very  marked  differences. 
PoLYZOA. — Salicornaria,  sp.  n. 
CcELENTERATA.  —  Two     fragments    of    a    hydroid 
)ophyte. 

Protozoa. — Numerous   foraminifera  belonging  to 

le    groups   already   indicated    as    specially   charac- 

ristic    of  these   abyssal   waters ;    together   with   a 

•anching  flexible  rhizopod,  having  a  chitinous  cortex 

f  Lidded  with  globigerinaej  which  encloses  a  sarcodic 

ledulla  of  olive-green  hue.     This  singular  organism, 

(  which  fragments  had  been  detected  in  other  dredg- 

igs,  here  presented  itself  in  great  abundance. 

One  or  two   small   Sponges,   which   seem  to   be 
iferable  to  a  new  group. 

On  Priday,  July  23,  we  tried  another  haul  at  the 
sine  depth  ;  but  when  the  dredge  came  up  at  1.30  p.m. 
i  was  found  that  the  rope  had  fouled  and  lapped  right 
rind  the  dredge-bag,  and  that  there  was  nothing  in 
ti3  dredge.  The  dredge  was  sent  down  again  at  3  p.m., 
ad  was  brought  up  at  11  p.m.,  with  upwards  of 
2cwt.  of  ooze. — We  got  from  this  haul  a  new 
Sicies  of  Fleurotoina  and  one  of  Dentalium ; 
trohicularia  nitida,  Muller;  Dacrydium  mtreum, 
Irell;  Ophiacantha  spinulosa,  M.  and  T.  ;  and 
Ohiocten  Jcrdyeri,  Lutken  ;  with  a  few  crustaceans 
a  1  many  foraminifera. 

H 


1 


98  THE  DEPTHS  OF  THE  SEA.  [chap. 

In  both  of  these  last  deep  dredgings  the  dredge 
brought  up  a  large  number  of  extremely  beautiful 
Folycystina,  and  some  forms  apparently  intermediate 
between  Folycystina  and  Sponges,  which  will  be 
described  shortly.  These  organisms  did  not  seem  to 
be  brought  from  the  bottom,  but  appeared  to  be  sifted 
into  the  dredge  on  its  way  up.  They  were  as  numerous 
adhering  to  the  outside  of  the  dredging-bag  as  within 
it.  During  the  soundings  taken  near  this  locality 
quite  a  shower  of  several  beautiful  species  of  the 
Folycystina  and  AcantJiometrina  fell  upon  the  chart- 
room  skylight  from  the  whole  length  of  the  sounding- 
line  while  it  was  being  hauled  in. 

We  were  now  steaming  slowly  back  towards  the 
coast   of  Ireland;    and    on   Monday,   July    26,  we 
dredged  in  depths  varying  from  557  to  584  fathoms 
(Stations  39-41)  in  ooze,  with  a  mixture  of  sand  and  | 
dead  shells.     In  these  dredgings  we  got  one  or  two 
very  interesting   alcyonarian  zoophytes,  and  several  | 
ophiurideans,  including  Opliiothrix  fragilis,  AmpMural 
ballii,   and    Ophiacantha    spinulosa.      Many   of   thej 
animals  were  most  brilliantly  phosphorescent,  and  wej 
were  afterwards  even  more  struck  by  this  phenomenon^ 
in  our  northern  cruise.     In  some  places  nearly  every-l 
thing  brought  up  seemed  to  emit  light,  and  the  mud| 
itself  was  perfectly  full  of  luminous   specks.    Th^ 
alcyonarian s,    the    brittle-stars,    and   some   annelids 
were  the  most  brilliant.     The  Fennatulce,  the  Virgu- 
laricB,  and  the  Gorgonice  shone  with  a  lambent  white 
light,    so  bright  that  it  showed  quite  distinctly  the 
hour  on  a  watch  ;  while  the  light  from  Ophiacanthi 
spimdosa  was  of  a  brilliant  green,  coruscating  fronj 
the  centre  of  the  disk,  now  along  one  arm,  now  alonr 


MAP.  111.]  THE  CRUISES  OF  THE  'PORCUPINE:  99 

j  nother,  and  sometimes  vividly  illuminating  the  whole 
'utline  of  the  star-fish. 

On  the  27th  we  dredged  in  862  fathoms  (Station  42), 

he  weather  heing  still  very  fine,  and  the  sea  quite 

;iiiooth.     The  bottom  was  ooze,  with  sand  and  dead 

hells.     Among  the  Mollusea  procured  were  a  new 

peeies  of  Fleuronectia,  Leda  abyssicola  (Arctic),  Leda 

\iessinensis    (a    Sicilian   tertiary   fossil),    Dentalkwi 

\igas  (sp.  n.),  Siplioiiodentalium  (sp.   n.),    Cerithium 

\ietula,  Amaura  (sp.  n.),  Columhella  haliceeti,  Cylichia 

yramidata    (Norwegian    and    Mediterranean),    and 

liany   dead    shells    of    Cavolma    trispmosa.      These 

itter  were  very  common  in  all  the  northern  dredg- 

iigs,  though  we  never  saw  a  living  specimen  on  the 

'irface. 

During   the  afternoon   we  took   a  series  of  inter- 

lediate  temperatures,  at  intervals  of  50  fathoms,  from 

le  bottom  at  862  fathoms  to  the  surface. 

On  the  28th  we  dredged  in  1207  fathoms  (Station 

3),  with  a  bottom  of  ooze.     A  large  Fusus  of  a  new 

)ecies  {F.  atteniiaius,  Jeffreys)  was  brought  up  alive, 

ith  two  or  three  Gephyrea^  and  an  example  each  of 

^phiocten  sericeum  and  Fchinocucumis  typica.     We 

>ain  dredged  on  the  29th  and  30th,  gradually  draw- 

ig  in  towards  the  coast  of  Ireland  in  865,  458,  180, 

ad  113  fathoms  successively  (Stations  44,  45).     In 

58  fathoms    (Station   45)    we   procured    a  broken 

cample  of  Briswga  endecacnemos,  previously  taken 

y    Mr.    Jeffreys   off   Valentia,    and    a   number    of 

iteresting  Mollusea  ;  and  in  458  and  180  fathoms 

stations  45  and  45<^)  an  extraordinary  abundance  of 

limal  life,  including  many  very  interesting  forms — 

^entalium  ahyssorum,  Aporrhals  serresiamis,  Solarivm 

H  2 


1 


100  THE  DEPTHS  OF  THE  SEA.  [chap. 

fallaciosuMy  Fusus  fenestratus,  with  abundance  of 
Caryophyllia  borealis,  and  all  the  ordinary  deep- 
water  forms  of  the  region. 

The  last  station,  45a,  gave  us  a  most  singular  as- 
semblage of  OpMurideans .  OpMoglypha  lacertosa 
was  in  large  numbers  and  of  extraordinary  size,  and 
associated  with  it  were  two  most  conspicuous  species, 
new  to  science ;  one  a  large  species  of  Ophiothria:, 
coming  near  O.  fragilis,  but  of  much  larger  size; 
the  disk  in  the  larger  specimens  25  mm.  in 
diameter,  and  the  span  from  tip  to  tip  of  the  rays 
275  mm.  The  colours  of  the  disk  are  very  vivid, 
purple  and  rose ;  and  all  the  plates  of  the  disk,  and 
the  dorsal  plates  of  the  arms,  are  studded  with 
delicate  spines.  Notwithstanding  its  totally  different 
aspect,  I  had  a  misgiving  that  this  might  yet  prove 
only  an  extreme  variety  of  O.  fragilis.  My  friend 
Dr.  LtJTKEN,  however,  protests  that  it  is  totally 
distinct.  On  such  a  question  I  bow  to  his  authority, 
and  dedicate  it  to  him,  doubts  and  all,  under  the  name 
of  Ophiothrix  lutkeni.  The  second  novelty  was  a  fine 
species  of  Ophionmsium, 

About  mid-day  on  Saturday,  the  31st  of  July,  we 
steamed  into  Queenstown.  Having  coaled  at  Haul- 
bowline  on  Monday,  the  2nd  of  August,  we  were 
moored  in  the  Abercorn  Basin,  Belfast,  after  a 
pleasant  return  passage  up  the  channel,  on  the 
evening  of  Wednesday,  the  4th. 

As  it  was  necessary  that  her  boilers  should  be 
thoroughly  cleared  out  after  having  been  so  long  at 
sea,  the  '  Porcupine'  did  not  leave  Belfast  till 
Wednesday,  the  11th  of  August;  when  she  pro- 
ceeded to  StornoAvay,  her  final  port  of  departure. 


jHAr.  III.]  THE  CRUISES  OF  THE  ' PORCUPINE:  101 

The  scientific  staff  consisted  of  Dr.  Carpenter, 
Vir.  P.  Herbert  Carpenter  (who  had  gone  through  his 
ipprenticeship  in  making  analyses  under  unfavourable 

.  *;ircumstances  in  the  former  cruise  with  Mr.  Hunter, 
md  was  now  prepared  to  undertake  this  task  on  his 
)wn  account),  and  myself;  and  our  intention  was,  in 
'iccordance  with  our  original  programme,  to  go  care- 
ully  over  again  the  region  which  we  had  examined 
n  the  '  Lightning,'  to  test  with  better  appliances  and 
laore  trustworthy   instruments    the  singular    distri- 

1  imtion  of  temperatures  in  the  'warm'  and  'cold' 
ireas,  to  map  out  as  accurately  as  we  could  the 
)aths  of  the  warm  and  cold  currents,  and  to  deter- 
jnine  the  influences  of  these  currents  upon  the 
I'haracter  and  distribution  of  animal  life. 
I   We   left  Stornoway  on  the   afternoon  of  Sunday 

i  jhe  15th  of  August,  and  made  straight  for  the  scene 
f  our  most  successful  'warm  area'  dredging  of  the 
ear  before.  We  were  equally  successful  on  this 
ccasion,  and  procured  several  good  specimens  of 
loUenia,  and  a  beautiful  series  of  Uyalonema,  ranging 
L'om  2  mm.  in  length  up  to  30  and  40  centimetres, 
nd  thus  giving  all  the  stages  in  the  development  of 
he  wonderful  '  glass  rope,'  and  proving  to  demon- 
jtration  its  relation  to  the  body  of  the  sponge — 
|)r.  J.  E.  Gray's  so-called  Carteria, 

The  most  interesting  novelty  however  which  re- 
.^arded  us  was  a  very  fine  Echinid  belonging  to  the 
''idaridse  to  which  I  had  given  the  name  Forocidaris 
urpurata  (Fig.  11).  I  believe  I  am  justified  in 
3ferring  this  handsome  species  to  the  genus  JPoroci- 
aris,  although  in  it  the  special  character  is  absent 
n  which  that  genus  w^as  founded  by  Desor.     Some 


102 


THE  DEPTHS  OF  THE  SEA.  [chap.  ni. 


Fig.  11.— rorocicfar is  i^wrpHrato,  Wrv^iLLE  Thomson.     Natural  size.     (No.  47.) 


HAP.  III.]  THE  CRUISES  OF  THE  'PORCUPINE:  103 

radioles,'  as  the  fossil  spines  of  Cidarites  are  usually 

3alled,  presenting  a  very  marked  character,  had  been 

:bund  in  various  formations  from  the  lower   oolite 

ipwards.  These  spines  are  paddle-shaped,  compressed, 

ongitudinally  grooved,  flattened  almost  into  plates, 

imd  strongly  serrated  on  the  edges.     In  the  nummu- 

[itie  beds  of  Yal-Dominico  near  Yerona  such  spines 

»vere  found  associated  with  plates  much  resembling 

hose  of  Cidaris,  but  with  the  unique  peculiarity  of  a 

jcow  of  holes  penetrating  the  test  in  the  areolar  space 

jpound  the  primary  tubercle.     This  character  our  new 

Urchin  does  not  possess,  but  the  radioles  have  the 

flatness,  the  longitudinal  strise,  and  the  serrated  edges 

3f  those  of  Forocidaris. 

I  do  not  attach  much  importance  to  the  perfora- 
tions in  the  plates.  Prom  Desor's  figures  they  are 
act  round  and  defined  in  outline,  but  lengthened  and 
somewhat  irregular,  and  they  radiate  from  the  inser- 
tion of  the  spine.  .  Our  species  has  a  set  of  depres- 
sions occupying  the  position  of  these  perforated 
grooves  which  are  undoubtedly  for  the  insertion  of 
the  muscles  moving  the  large  long  spines,  and  as  the 
test  is  thin  these  grooves  might  readily  penetrate  the 
plate,  or  so  nearly  penetrate  it  as  to  be  worn  into 
boles  by  very  little  drifting  or  wear. 

Our  •  recent  species  and  the  eocene  form  have 
another  character  in  common ;  the  areolar  circles 
are  not  well  defined,  and  the  areolae  tend  to  become 
confluent. 

Scattered  plates  only  of  this  genus  have  been 
found  fossil,  and  the  ovarial  plates  were  till  now 
unknown.  They  present  a  very  singular  character, 
which   is   certainly  of  generic   value.      The   ovarial 


4 

104  THE  DEPTHS  OF  THE  SEA.  [chap,  nt 

aperture  does  not  penetrate  the  plate,  but  perforates 
a  membrane  which  fills  up  a  diamond-shaped  space, 
one-half  of  which  is  cut  out  of  the  outer  edge  of  the 
ovarial  plate  in  the  form  of  a  large  triangular  notch, 
while  the  other  half  is  formed  by  a  separation  into  a 
like  notch  of  the  two  upper  interradial  plates,  in  the 
middle  line   of  the   interradial   space.     The  charac-  \ 
teristic  paddle-shaped  spines  are  ranged  in  several  \ 
rows  round  the  mouth.     The  large  spines  round  the  j 
equator  of  the  corona  are  diverse  in  form,  some  of  j 
them  cylindrical,  only  slightly  tapering  towards  the  | 
tip,  and  others  bulging  out  and  thick  near  the  neck  j 
and  coming  somewhat  rapidly  to  a  sharp  point.    The  ( 
colouring  of  the  animal  is  very   remarkable.     The  | 
short  spines  covering  the  test  are  of  a  rich  purple,  \ 
and  a  purple  of  even  a  deeper  and  richer  hue  dyes  i 
about  one-third  of  the  length  of  the  spine,  from  the  j 
head  of  the  spine   outwards,  ending   abruptly  in  a  [ 
sharply  defined  line.     The  spine  beyond  this  purple  j 
portion  is   of  a  beautiful  pale  rose   colour.      Two  ; 
mature  examples  of  this  fine  species  were  found,  and  i 
two  young  ones,  one  nearly  half-grown  and  the  other  I 
much  smaller. 

We  now  moved  slowly  to  the  northward  towards 
the  Eseroe  Bank,  and  soundings  were  taken  to  fix  as  i 
closely  as  possible  the  point  of  passage  from  the  warm  I 
water  into  the  cold  :  a  temperature  sounding  taken  in  1 
lat.  59°  37',  long.  T  40',  gave  a  depth  slightly  less 
than  that  of  the  '  Holtenia  ground,' — 475  fathoms, — 
with  a  slightly  higher  bottom  temperature,  7°'4  C. ;  and 
at  Station  50,  lat.  59°  54',  long.  T  52',  with  a  depth  of 
335  fathoms,  the  minimum  temperature  had  risen  to 
7°-9  C.     A  sounding  at  Station  51,  lat.  60°  6',  long. 


CHAP.  III.]  THE  CRUISES  OF  THE  'PORCUPINE:  105 

I  8°  14',  gave  MO  fathoms,  and  a  bottom  temperature  of 
I  5°*5  C,  showing  that  we  were  passing  into  another  set 
I  of  conditions ;    and  at  Station  52,  lat.   60°  25',  long. 
i  8°  10',  only  a  few  miles  further  on,  with  a  depth  of 
,  384  fathoms,  nearly  the  same  as  that  of  Station  20, 
i  the  thermometers  recorded  a  minimum  of  >-0°-8  C. 
I  We  now  altered  our  course  towards  the  east-south- 
I  east,  and,  after  a  run  of  about  25  miles,  sounded  in 
490  fathoms,  with  a  bottom  temperature  of  —  l°'l  C. 
i  The  following  six  stations,  Nos.  54  to  59,  were  all  in 
!  the  cold  area  with  a  temperature  below  the  freezing- 
point  of  fresh  water.  At  the  last  station,  No.  59,  lat.  60° 
21',  long.  5°  41',  at  a  depth  of  580  fathoms,  the  guarded 
thermometer  recorded  the  lowest  temperature  which 
was  met  with  - 1°-3  C.  While  we  were  passing  through 
the   cold   area'  and   making   these   observations,  the 
weather  was  extremely  settled  and  fine,  and  under  the 
careful  management  of  Captain  Calver  all  our  appli- 
ances worked  admirably.   The  temperatures  were  noted 
in  every  case  by  the  same  pair  of  Miller-Casella  ther- 
mometers, which  were  sometimes  compared  with  other 
instruments  and  found  to  give  perfectly  accurate  indi- 
cations, even  after  being  so  frequently  subjected  to 
prodigious  pressure.     The  sounding  instruments  and 
the  dredges  never  failed,  and  an  ingenious  device,  for 
which  we  are  indebted  to  our  Captain,  enabled  us 
sometimes  to  multiply  our  prizes  a  hundred-fold.     A 
number   of    tangles    of    teazed-out    hemp,    like   the 
*  swabs '  for  cleaning  the  deck,  were  hung  in  a  way 
which  will  be  explained  hereafter  at  the  bottom  of  the 
dredge.    These  hempen  tangles  swept  by  the  sides  of 
the  dredge,  pulling  along  and  picking  up  everything 
which  was   moveable   and  rough.     As  echinoderms. 


106  THE  DEPTHS  OF  THE  SEA.  [chap.  m. 

crustaceans,  and  sponges  were  very  numerous  in  the 
cold  area,  the  tangles  often  came  up  absolutely  loaded, 
while  there  was  but  little  within  the  dredge-bag. 

In    the    course   of    the   last    series    of   dredgings  I 
we   crossed  the  position  of  the  bank  on  which  we  j 
got    large    specimens    of    Terehratula    cranium    in 
so  great   abundance  the  year  before,  but   we   could  \ 
not  find  it.     The  bank  appears  to  be  of  very  limited  ' 
area,  and  both  on  this  occasion  and  on  the  previous 
one  the  sky  was  so  overcast  for  several  days  together,  j 
just  when  we  were  in  this  neighbourhood,  that  it  was  ' 
impossible  to  fix  the  position  either  of  the  'Lightning' 
or  of  the  '  Porcupine '  by  observation.    A  dead-reckon- 
ing is  of  course  kept  under  great  disadvantages  wh^ 
the  vessel  is  drifting  for  the  greater  part  of  the  time 
half  anchored  by  a  dredge. 

Erom  Station  59  we  proceeded  northward  to  Thors- 
havn,   where  we  were  warmly  received  by  our  kind  I 
friend  Governor  Holien,  who  had  been  forewarned  of 
our  visit,  and  at  once  came  off  in  his  barge  to  welcome 
us.     Governor  Holten  was  uncommonly  proud  of  this 
barge,  and  he  had  some  reason.   She  was  a  very  hand- 
some trim  boat ;  and,  manned  by  a  dozen  stout  Eaeroese  \ 
boatmen  in  their  neat  uniform,  and  with  the  Danish 
ensign  flying  at  the  stern,  and  our  handsome  friend ; 
mufiied  in  his  military  cloak,  and  with  a  thick  hood  ^ 
to  keep  out  the  somewhat  palpable  and  intrusive  'cli- 
mate' of  FeiBroe,  she  looked  all  that  could  be  desired. 
When  the  Governor  came  on  board,  he  proposed  to  | 
Captain  Calver  to  try  a  race  with  him  for  the  honour  i 
of  old  England  and  the  white  ensign.     Some  of  us 
were  going  ashore,  and  when  the  Governor  came  up  j 
from  the  cabin  our  whale-boat  was  lying  alongside 


CHAP.  III.]  THE  CRUISES  OF  THE  'PORCUPINE:  107 

with  twelve  blue-jacketed  Shetlanders  sitting  like 
statues,  their  white  oars  glittering  in  the  sun.  The 
Governor  looked  with  the  critical  eye  of  a  sailor  at 
the  two  boats, — he  still  spoke  lovingly  of  the  '  Maid 
of  Fsferoe/  but  I  suppose  he  saw  that,  as  Tennyson 
says,  '  we  were  all  of  us  Danes ; '  and  the  question 
of  a  trial  of  strength  lapsed  by  mutual  consent ! 

We  were  obliged  to  remain  a  few  days  at  Thorshavn 
replenishing  in  various  ways,  and  while  there  we  were 
very  anxious  to  have  had  an  opportunity  of  seeing 
iMyling  Head — a  magnificent  cliff  at  the  north-western 
point  of  StromcJe,  which  falls  perpendicularly,  even 
slightly  overhanging  its  base,  from  a  height  of  upwards 
3f  2,000  feet  into  the  sea.  The  tide  runs  among 
md  round  these  islands  like  a  mill-race,  and  the 
jrovernor  told  us  that  if  we  started  with  the  morning 
iood,  and  our  vessel  kept  pace  w  ith  the  tide,  we  might 
nake  the  circuit  of  the  island,  passing  under  Myling, 
md  returning  to  Thorshavn  in  six  hours.  If  we  did 
lot  carry  the  tide  with  us,  it  became  a  matter  of  dif- 
iculty  only  to  be  achieved  at  considerable  expense 
)oth  of  fuel  and  time. 

We  found  that  high  water  would  occur  on  the  fol- 
owing  Monday,  Aug.  23,  at  4  o'clock  in  the  morning ; 
tnd  as  the  weather  was  brilliant  up  to  the  evening 
>f  Sunday — unusually  brilliant  for  those  regions — we 
nade  all  our  arrangements  in  high  hope  of  a  pleasant 
rip,  as  we  had  persuaded  our  kind  host  and  hostess 
o  accompany  us.  With  the  first  dawn  of  Monday 
Horning  it  was  blowing  and  pouring,  and  we  were 
bliged  to  defer  our  visit  to  the  celebrated  headland 
0  some  possible  future  opportunity. 
;  The   next  morning   was   fine   again,  and   we   left 


I 


108  THE  DEPTHS  OF  THE  SEA.  [chap.  iii. 

Thorshavn  about  noon,  steaming  east  by  south,  so 
as  to  cross  the  deep  channel  between  Eseroe  and 
Shetland.  Our  first  two  stations  were  on  the  Fseroe 
plateau,  at  depths  a  little  over  a  hundred  fathoms,  but' 
the  third  sounding,  taken  in  the  evening  of  the  24jth: 
at  a  depth  of  317  fathoms,  gave  a  bottom  temperature! 
of  —  0''-9  C. ;  we  were  therefore  once  more  in  the  cold' 
current.  Having  kept  the  same  course  under  easyi 
steam  during  the  night,  we  took  a  sounding  next; 
morning,  lat.  61°  21'  N.,  long.  3°  44'  W.,  at  a  depth  ofi 
640  fathoms,  with  a  bottom  temperature  of  —  1°-1  Ci 
A  haul  of  the  dredge  brought  up  rolled  pebbles  andj 


Fig.  12. — Pourtal^ia  jeffreysi,  Wyville  Thomson.    Slightly  enlarged,  i    (No.  64.) 

fine  gravel  with  few  animal  forms,  but  among  theml 
one  of  extraordinary  interest,  a  large  specimen  of  a| 
fine  species  of  the  genus  Fourtalesia,  a  heart-urchinJ 
one  of  whose  congeners  had  been  discovered  byl 
M.  de  Pourtales  in  the  gulf- stream  explorations  of^ 
the  American  coast,  and  a  second  by  Mr.  Gwyi^ 
Jefireys  near  Eockall.  The  present  example  (Eig.  12^ 
was  much  larger  than  either  of  those  previously 
dredged,  and  it  appeared  to  be  specifically  distinct. 

^  I  have  the  pleasure  of  dedicating  this  interesting  species  to  oui 
accomplished  colleague,  J.  Gwyn  Jeffreys,  F.R.S. 


CHAP.  III.]  THE  CRUISES  OF  THE  'PORCUPINE:  109 

The  shell  is  singularly  unlike   that  of  any  other 
known  living  eehinoderm.     It  is  about  tAvo  inches  in 
length,  almost  cylindrical,  ending  posteriorly  in  a  blunt 
rostrum,   and  the   anterior  extremity   is    truncated. 
The    surface    of  the    shell    is    covered    with    short 
spatulate  spines,  and  near  the  anterior  end  there  is 
a  kind  of  fringe  of  long  thin  cylindrical  spines,  especi- 
ally congregated  on  the  upper  surface.     The  mouth  is 
at  the  bottom  of  a  deep  anterior  and  inferior  groove, 
and  the  excretory  opening  is  at  the  bottom  of  a  pit 
on  the  dorsal  surface,  above  the   terminal  rostrum. 
The  arrangement  of  the  ambulacra  is  most  peculiar. 
jThe  four  ovarial  openings  and  the  madreporic  tubercle 
jare  on  the  dorsal  surface,  just  above  the  truncated 
'anterior  end   at  the  base  of  which  the  mouth  lies, 
md  the  three  ambulacral  vessels  of  the  '  trivium'  take 
I  short  course  from  the  oral  vascular  ring,  one  along 
the  centre  of   the  anterior  face,  and  the  other  two 
pound  its  edges  to  meet  in  a  ring  surrounding  the 
)varial  openings.      The  two  vessels  of  the  '  bivium  ' 
lave  a  very  singular  course.      They  run  back  into 
he  great  posterior  prolongation  of  the  shell,  on  the 
ddes  of  which  they  form  long  loops,  sending  conical 
vater-feet  through  single  pores  in  long  double  lines  of 
omewhat  irregularly-formed  ambulacral  plates,  which 
inally  converge  in  a  point  a  considerable  distance 
)ehind  the  point  of  convergence   of  the  three  am- 
'ulacra  of  the  bivium.     Between  these  two  points  of 
onvergence,   which  are  both  on  the  middle  line  of 
he  back,  several  plates  are  intercalated.     We  have 
hus  the  three  anterior  ambulacra  ending  in  their 
cular  plates,    meeting    at   one   point,    where   there 
re  likewise  four  genital  plates,  and  the  madreporic 


110  THE  DEPTHS  OF  THE  SEA.  [chap.  hi. 


tubercle;  and  the  two  posterior  ambulacra,  with 
their  ocular  plates,  meeting  at  another  point  and 
forming  a  kind  of  secondary  apex.  The  fifth  genital 
plate  is  obsolete.  The  specially  interesting  point  is 
that,  while  we  had  so  far  as  we  were  aware  no  living 
representative  of  this  peculiar  arrangement  of  what 
is  called  '  disjunct '  ambulacra,  we  have  long  been 
well  acquainted  with  a  fossil  family,  the  Dysasteridce, 
possessing  this  character.  Many  species  of  the 
genera  Dysaster,  Agassiz,  Collyrites,  Desmoulins, 
Metaporhlnus,  Michelin,  and  Grasia,  Michelin, 
are  found  from  the  lower  oolite  to  the  white  chalk, 
but  there  the  family  had  previously  been  supposed  to 
have  become  extinct. 

The  next  attempt  was  one  of  our  very  few  entirely 
unsuccessful  hauls,  the  dredge  coming  up  empty. 
This  we  attributed  to  an  increase  of  wind  and  swell, 
and  consequent  drift  on  the  vessel,  which  seemed  to 
have  prevented  the  dredge  from  reaching  the  ground. 

We  devoted  the  morning  to  a  series  of  temperature  I 
soundings  at  intervals  of  50  fathoms  from  the  surface ' 
to  the  bottom,  and  this  we  accomplished  in  a  very! 
satisfactory  manner,  with  results  which  will  be  fully ' 
discussed  hereafter.  After  a  rapid  descent  for  the 
first  50  fathoms  the  next  150  fathoms  maintained! 
a  high  and  a  tolerably  equable  temperature,  and 
there  was  then  a  rapid  fall  between  200  and  300 
fathoms,  the  thermometer  at  the  greater  depth  indi-i 
eating  O'C.  Prom  300  fathoms  to^the  bottom  thej 
temperature  fell  little  more  than  a  degree.  "  Thus' 
the  entire  mass  of  water  in  this  channel  is  nearlyj 
equally  divided  into  an  upper  and  lower  stratum,  the; 
lower  being  an  Arctic  stream   of  nearly  2,000  feetj 


iiAP.  HI.]  THE  CRUISES  OF  THE  '  PORCUPINE:  \l\ 

iieep,  flowing  in  a  south-westerly  direction,  beneath 
kn  upper  stratum  of  comparatively  warm  water 
Inoving  slowly  towards  the  north-east ;  the  lower 
[balf  of  the  latter,  however,  having  its  temperature 
jsonsiderably  modified  by  intermixture  with  the 
fetratum  over  which  it  lies."  ^ 

Our    next  few    dredgings  were    on  the  Shetland 

plateau,    in    depths   under    100   fathoms,    and   over 

ground   already   carefully  worked  by    our   colleague 

Mr.   Gwyn   Jeffreys.       We  got    few    novelties,    but 

)wing  to  our   very  eflPective  dredging  appliances  we 

:ook  some  of  the  '  Haaf '  rarities,  such  as  Fusus  nor- 

wgicus,  Chemn.  ;  Fusus  berniciensis,  King  ;   Fleuro- 

toma  carinatum,  Bivona  ;  in  considerable  numbers. 

The  hempen  tangles  stood  us  in  good  stead  with  the 

)chinoderms.     On  one  occasion  the  dredge  brought  up 

it  a  single  haul,  in  the  bag  and  on  the  tangles,  cer- 

pinly  not  less   than  20,000  examples  of  the  pretty 

ittle  urchin.  Echinus  no7wegicus,  D.  and  K. 

j    On  the  28th   of  August  we  anchored  in  Lerwick 

jEarbour.      We   remained   at  Lerwick    several   days 

aking  in  necessary  supplies,  looking  at  the  geology 

md  the  many  remarkable  antiquities  of  the  neigh- 

pourhood,  and  ransacking  the  haberdashers'  shops  for 

f.hose  delicate  fleecy  fabrics  of  wool  which  imitate  in 

I  scarcely  grosser  material,  and  with  almost  equal 

lelicacy  of  design,  the  fretted  skeletons  of  ILoltenia, 

Euplectella,  and  Aphrocallistes. 

In  this  earlier  part  of  the  cruise  nearly  all  the 
iredgings  had  been   confined  to  the  cold  area,  and 

^  Dr.  Carpenter,  in  "  Preliminary  Report  on  the  Scientific  Explora- 
ion  of  the  Deep  Sea,  1869."  (Proceedings  of  the  Royal  Society,  vol. 
Lvii.  p.  441.) 


■ 


112  THE  DEPTHS  OF  THE  SEA.  [chap,  m 

over  that  region  we  had  found  a  great  uniformity  of 
conditions.  As  already  mentioned,  the  average  bottom 
temperature  throughout  was  a  little  below  the  freezing- 
point  of  fresh  water,  and  it  sometimes  fell  to  nearly 
2°  C.  below  the  zero  of  the  centigrade  scale.  The 
bottom  was  uniformly  gravel  and  clay,  the  gravel  on 
the  Scottish  side  of  the  channel  consisting  chiefly  of 
the  debris  of  the  laurentian  gneiss  and  the  other 
metamorphic  rocks  of  the  North  of  Scotland,  and  the 
devonian  beds  of  Caithness  and  Orkney.  On  the 
Pseroe  side  of  the  channel,  on  the  other  hand,  the 
pebbles  were  chiefl.y  basaltic.  This  difference  shows 
itself  very  markedly  in  the  colour  and  composition  of 
the  tubes  of  annelids,  and  the  tests  of  sundry  fora 
minifera.  The  pebbles  are  all  rounded,  and  the 
varying  size  of  the  pebbles  and  roughness  of  the 
gravel  in  different  places  give  evidence  of  a  certain 
amount  of  movement  of  material  along  the  bottom,    j 

There  seems  to  be  but  little  doubt,  from  thet 
direction  of  the  series  of  depressions  in  the  isothermal  j 
lines  of  the  region  (PL  7),  that  there  is  a  direct  move-j 
ment  of  cold  water  from  the  Spitzbergen  Sea  into  the' 
North  Sea,  and  that  a  branch  of  this  cold  indraughtj 
passes  into  the  P^roe  Channel.  The  fauna  of  the  colds 
area  is  certainly  characteristic,  although  many  of  itss 
most  marked  species  are  common  to  the  deep  water; 
of  the  warm  area  whenever  the  temperature  sinks 
below  2°  or  3°  C. 

Over  a  considerable  district  in  the  Pseroe  Channel 
there  is  a  large  quantity  of  a  sponge  which  is  pro- 
bably identical  with  Cladorliiza  ahjssicola,  Saiis,| 
dredged  by  G.  O.  Sars  in  deep  water  off  the 
Loffoten    Islands.      This     sponge   forms   a   kind   of 


^HAP.  HI.]         THE  CRUISES  OF  THE  *  PORCUPINE:  \  \  3 


lush  or  shrub,  which  appears  to  clothe  the  bottom 

1  some  places  over  a  large  area  like  heather  on  a 

boor.     There  are  at  least  three  species.     In  one  the 

Jranches  are  strict  and  rigid ;  while  in  another  the 

irangement  is  more  lax,   side  branches  coming  off 

from  a  flexible  central  rachis  like  the  barbs  from  the 

laft  of  an  ostrich  feather.     The  branches  seem  in 

»me  cases  to  be  from  50  to  80  centimetres  in  height, 

id  the  stems  near  the  base  are  2  to  3  centimetres  in 

ameter.     The  stem  and  branches  consist  of  a  firm 

intral    axis,    semi-transparent    and    of   a    peculiar 

iUowish   green  colour;    composed  of  a  continuous 

)my  substance  filled  with  masses  of  needle-shaped 

iicules  arranged   longitudinally  in   dense  sheaves. 

!iis  axis  is  overlaid  by  a  soft  bark  of  sponge  sub- 

iance  supported  by  needle-shaped  spicules,  and  full 

(  the  bihamate  '  spicules  of  the  sarcode '  so  charac- 

Iristic  of  the  genus   Esperia  and  its  allies.     The 

cjiist  is  covered  with  pores,  and  rises  here  and  there 

ifco  papillae  perforated  by  large  oscula.     This  sponge 

3 pears  to  belong  to  a   group   allied   to  the   Espe- 

rLdse,    and  perhaps    even    more    closely   allied    to 

sue  of  the  fossil  branching  forms  whose    remains 

a|3  so  abundant   in  some  beds   of   the  cretaceous 

i:riod.      A   still   finer   species  of  the    same    group 

V.S  dredged   by   Mr.  Gwyn   Jeffreys    in    the    first 

(uise  of  the  following  year. 

A.I1  other  peculiar  sponge  (Eig.  13)  is  very  abundant 
ft  i  of  a  large  size.  This  form  was  admirably  described 
1)  Professor  Loven — unaccountably  under  the  name 
^ySyalonema  horeale.  It  is  certainly  very  far  from 
■^.'alonema.  It  is  more  nearly  allied  to  Tethya,  for 
tl?  body  of  the  sponge  must  certainly  be  referred  to 

;  I 


114 


THE  DEPTHS  OF  THE  SEA. 


I 


[chap.  in. 


the  corticate  type,  though  it  differs  from  all  the  other 
known  members  of  the  order  in  being  supported  on  a 
long  symmetrical  stalk  formed,  as  Professor  Lov^n 
has  shown,  of  sheaves  of  short  spicules  bound  together! 


Fig.  13. — Stylocordylabormlis,  ho\ks  (Up.  j.     Natural  size      (No.  64.) 

by  horny  cement.  A  tuft  of  delicate  fibres  fixes  the 
base  of  the  stem  in  its  position.  Professor  Oscaii 
Schmidt,  in  his  *' Outline  of  the  Sponge  Fauna  oi 
the  Atlantic,"  refers  this  form  to  his  genus  Cometellc 


CHAP.  IN.]         THE  CRUISES  OF  THE  ' PORCUPINE:  1 1 5 

land  this  he  associates  with  Suberites,  Tethya  greatly 
i restricted,  and  one  or  two  other  generic  groups,  to 
form  a  family  the  Suberitidinae,  a  part  of  the  old 
order  Corticata3,  which  order  he  now  proposes  to 
dismember.  I  doubt  if  this  arrangement  will  hold 
good,  for  the  silicious  sponges  w4iose  skeleton  con- 
sists mainly  of  radiating  sheaves  of  long  spicules, 
form  a  conspicuous  and  natural  assemblage.  Stylo- 
cordyla  is  evidently  nearly  related  in  habit  and 
general  character  to  the  Mediterranean  stalked 
sponge  figured  by  Schmidt  under  the  name  of 
Tetilla  enplocamos} 

Eoraminifera  are  not  very  abundant  in  the  cold 
larea,  though  here  and  there  in  isolated  patches 
large  numbers  of  large  and  remarkable  forms  came 
up  on  the  '  hempen  tangles.'  These  were  principally 
of  the  Arenaceus  type.  On  one  occasion,  at  Station 
51,  one  of  the  intermediate  dredgings  between  the 
w^arm  area  and  the  cold,  the  tangles  brought  up 
X  multitude  of  tubes  three-quarters  of  an  inch  to 
in  inch  long,  composed  of  sand- grains  cemented 
together,  and  with  a  slight  appearance  externally  of 
jeading,  as  if  they  were  divided  into  segments. 
During  the  '  Lightning '  excursion  the  year  before, 
m.  the  middle  bank  along  with  the  specimens  of 
Terehratula  a^anium,  we  had  found  in  abundance  a 
sandy  LUuola  with  very  much  the  same  appearance, 
jxcept  that  at  one  end  the  Lituolce  had  a  promi- 
lent  mouth,  and  on  breaking  them  open  this 
nouth  w^as  repeated,  definitely  moulded  of  peculiarly 

^  Die  Spongien  der  Kiiste  von  Algier.  Von  Dr.  Oscar  Schmidt 
-^rofessor  der  Zoologie  and  vergleichenden  Anatomie,  Director  des 
iUiidschaftliclien  zoologischen  Museums  zu  Gratz.     Leipzig,  18()8. 

I  2 


116  THE  DEFTHS  OF  THE  SEA.  [chap.  iii. 

! 
coloured  sand  grains,  for  every  chamber  of  the  series 
into  which  the  test  was  divided.    The  new  form,  how- 
ever, was  found  not  to  be  divided  into  chambers,  but 
to  have  its  cavity  continuous  throughout,  '*  though 
traversed    in  every   part  of  its   length  by   irregular 
processes,  built  up  partly  of  sand-grains  and  partly  of 
sponge-spicules,"  resembling  those  described  by  Dr. 
Carpenter  in  the  gigantic  fossil  form  Parkeria}     One 
extremity  of  this  chamber  is  arched  over,  spaces  being 
left  between  the  agglutinated   sand-grains,   through  ; 
which  it  appears  that  the  gelatinous  being  within  com-  j 
municates  with  the  outer  world  by   protruding  its  ; 
sarcode  processes.     The  other  end  was  so   constantly  - 
broken     oflP,    leaving    a    rough    fracture,    that    Dr.  ; 
Carpenter   was   inclined    to   believe    that  this  form  ; 
to  which  he  gave  the  generic  name  of  Botellina,  grew  I 
attached  to  the  bottom  or  to  some  foreign  body.  \ 

The  cold  area  teems  with  echinoderms.  In  the  i 
channel  north  and  west  of  Shetland,  we  added  to  the  ,; 
fauna  of  the  British  area  besides  a  large  number  of  \ 
species  new  to  science,  nearly  every  one  of  the  forms  i 
described  by  the  Scandinavian  naturalists  as  inhabit-  | 
ing  the  seas  of  Norway  and  Greenland.  \ 

In  comparatively  shallow  water  Cidaris  hystrix  \ 
was  most  abundant,  and  of  large  size.  The  large  \ 
form  o£ UchitiMs flemingii,  Ball,  was  rare;  but  every 
haul  at  all  depths  brought  up  some  variety  or  other 
which  was  referred  with  doubt  to  K  elegans,  D.  and 
K.,  to  one  or  other  form  of  U,  norvegicus,  D.  and  K., 
or  to  E.  rarituberculatus^  G.  O.  Sars  ;  and  although  it 
may,  perhaps,  be  necessary  still  to  describe  all  these 
which  certainly  in  their  extreme  forms  present  very 

^  Philosophical  Transactions,  1869,  p.  806. 


CHAP.  III.]       th:e  cruises  of  the  '  porcupine:  117 

marked  differences  as  distinct  species,  after  having 
gone  over  some  thousands  of  them — some  hr ought 
up  in  nearly  every  haul  of  the  dredge  from  Pseroe  to 
Gibraltar — I  am  inclined  to  suspect  that  they  may 
be  all  varieties  of  Echinus  flemingii,  I  have  already 
alluded  to  the  countless  myriads  in  which  the 
small  form  of  E,  norvegicus,  D.  and  K.,  15  mm.  in 
diameter,  swarms  on  the  '  Haaf '  fishing  banks. 
These  little  urchins  are  mature  so  far  as  the  develop- 
ment of  their  generative  products  is  concerned ;  and  I 
suspect  from  the  abundance  of  three  sizes,  that  they 
attain  their  full  size  in  two  years  and  a  half  or  three 
years;  but  in  colouring,  in  sculpture,  and  in  the 
form  of  the  pedicellariae,  I  do  not  see  any  character  to 
distinguish  them  from  a  form  four  times  the  size, 
common  in  deep  water  off  the  coast  of  Ireland; 
nor,  again,  can  I  distinguish  these  last  by  any  definite 
character  which  one  would  regard  as  of  specific  value 
from  the  shallow  water  form  of  Echinus  flemingii,  as 
large  as  the  ordinary  varieties  of  E.  sphcera. 

The  Shetland  variety  of  Equus  cahallus  is  certainly 
not  more  than  one-fourth  the  size  of  an  ordinary 
London  dray-horse,  and  I  do  not  know  that  there  is 
any  good  reason  why  there  should  not  be  a  pony 
form  of  an  urchin  as  well  as  of  a  horse. 

Professor  Alexander  Agassiz^  has  discovered  that 
the  Florida  species  of  Echinocyamus  is  nothing 
more  than  the  young  of  a  common  Florida  clypeas- 
troid,  Stolonoclypus  prostratus,  Aa.,  and  he  sug- 
gests the  possibility  of  our  Echnocyamus  angulosiis, 
Leske,  being  one  of  these  stunted  '  pony  '  varieties, 
or  undeveloped  young,  either  of  the  American  Stolo- 

^  Bulletin  of  the  Museum  of  Comparative  Zoology,  No.  9,  p.  291. 


118  THE  DEPTHS  OF  THE  SEA.  [chap.  hi. 


noclypus,  the  pluteus  *  pseudemliryo '  having  heen 
carried  along  and  distributed  by  the  gulf-stream,  or 
of  some  European  deep-water  clypeastroid  hitherto 
unknown. 

The  three  so-called  species  of  the  genus  Toxo- 
pneustes  of  the  cold  area  must,  I  fear,  submit 
to  fusion.  T.  plctus,  Norman,  and  T.  pallidus^ 
G.  O.  Sars,  are  certainly  varieties  of  T.  drobaohi- 
ensis,  O.  E.  Muller. 

The  young  of  Brissopsis  lyrifera^  Eorbes,  were 
abundant  at  all  depths,  but  mature  examples  did 
not  occur  beyond  200  fathoms,  and  were  larger 
and  more  abundant  from  50  to  100  fathoms.  Tri- 
pylus  fragilis,  D.  and  K.,  a  rather  scarce  Scandinavian 
form,  was  added  to  the  British  fauna ;  several  speci- 
mens having  been  taken,  unfortunately  usually 
crushed  on  account  of  its  great  delicacy,  in  the  I 
deeper  and  colder  hauls.  Magnificent  specimens  of  ^ 
the  handsome  heart -urchin,  Spatangus  raschi,  were 
very  abundant,  associated  in  the  same  zone  of  depth 
with  Cidaris.  \ 

Star-fishes  were  verv  numerous,  rare  and  new 
species  sometimes  actually  crowding  the  hempen 
tangles.  The  two  species  of  Brisinga,  B.  endeca- 
cnemos,  Absj.,  and  B.  coronata,  G.  O.  Sars,  came  up 
occasionally  and  were  always  regarded  as  prizes, 
although  it  was  a  matter  of  some  difficulty  to  ex- 
tricate their  spiny  arms  one  after  the  other  from  the 
tangles;  they  were  scarcely  ever  within  the  dredge. 
Salaster  papposus,  Eorbes,  apparently  their  nearest  of 
kin  though  far  removed,  was  represented  abundantly 
by  a  very  pretty  deep-water  variety,  with  ten  arms 
about    forty    millimetres    across    from    tip    to    tip, 


SAP.  III.]         THE  CRUISES  OF  THE  'PORCUPINE: 


119 


f  a  bright  orange-scarlet  even  at  Station  6i,  at  a 
piepth  of  640  fathoms ;  and  we  dredged  abundantly 
k   furcifer,  D.  and  K.  (Pig.  14),  previously  known 


Fio.  14.  -Soluster  urcifer,  Von  Dubkn  and  Kohen.     Natural  sizj.     (Xo.  55.) 

nly  in  the  Scandinavian  seas.     Pedicellaster  typictis, 
Jars,  occurred  but  sparingly,  and  more  frequently  the 


Pio.  I&.—Kpretkrasterhispidus,  Wvville  Thomson.     Dorsal  aspect.     Twice  the  natural  size. 

(No.  57.) 

pretty  biscuit-like  Astrogonium   granulave,  MtJLLER 
and  Troschel.     A.  phryjianam,  O.  P.  MItller,  and 


120  'PHE  DEPTHS  OF  THE  SEA.  [chap.  id. 

Asteropsls  pulvillus,  O.  P.  Muller,  were  not  met 
with  beyond  the  100-fathom  line.  A  curious  little 
group  of  cushion  stars,  hitherto  supposed  to  be  con- 
fined to  higli  latitudes,  were  represented  by  Fteraster 
militaris,  M.  and  T.,  and  P.  pulmllus,  Sars,  and  by 
two  forms  new  to  science, — one,  Koreth raster  his- 
pidus,  sp.  n.,  with  the  whole  of  the  upper  surface 
covered  with  long  free  paxillse  like  sable  brushes  (Fig. 
15),     Ranges  of  delicate  spatulate  spines  border  the 


Fro.  16. —^?/me);as^er  pel'ZMC'id?^'?,  WvvitLE  Thomson.     Ventral  aspect.    Natural  size.    ^No.  69) 

arabulacral  grooves.  As  in  Tteraster,  there  is  a  double 
row  of  conical  water  feet.  The  other  genus  (Fig- 16) 
is  perhaps  even  more  remarkable.  The  star-fish  is 
very  flat,  the  dorsal  surface  covered  with  short  paxilloo 
which  support  a  membrane  as  in  Tier  aster.  A  row 
of  spines  fringing  the  ambulacral  grooves  is  greatly 
lengthened  and  webbed,  and  the  web  running  along 
the  side  of  one  arm  meets  and  unites  with  the  web 


CHAP.  III.]  THE  CRUISES  OF  THE  ♦  PORCUPINE:  121 

of  the  adjacent  arm,  so  that  the  angles  between  the 
iarms  are  entirely  filled  up  by  a  delicate  membrane 
jstretched  on  and  supported  by  spines,  and  the  body 
(thus  becomes  regularly  pentagonal.  There  is  no  trace 
on  the  ventral  surface  of  the  arms  of  the  trans- 
verse ranges  of  membranous  comb-like  plates  which 
are  so  characteristic  in  Pteraster, 

By  far  the  most  abundant  and  conspicuous  forms 
among  the  star-fishes  in  deep  water  were  the  genera 
Asti'opecten  and  Ar chaster,  and  their  allies.  At  one 
to  two  hundred  fathoms  the  small  form  of  Astro- 
pecten  irregularis,  A.  acicularis  of  Norman,  literally 
swarmed   in  some  places,  usually  in  company  with 

>  the  small  form  of  Luidia  savignii,  M.  and  T.,  L, 
sarsii,  D.  and  K.  I  feel  no  doubt  that  these  two 
porms,  A.  acicularis  and  Jj.  sarsii,  are  mere  deep- 
fwater  varieties  of  the  forms  which  attain  so  much 
larger  proportions  in  shallow  water.  Mr.  Edward 
Waller  took  charge  of  Mr.  Gwyn  Jeffreys'  yacht 
during  the  summer  of  1869,  on  a  dredging  cruise  off 
the  south  coast  of  Ireland.  He  worked  principally 
about  the  100-fathom  line  and  a  little  within  it,  and 
procured  a  magnificent  series  both  of  Astropecten  and 

-*  Luidia  showing   a   gradual    transition    through    all 

)  intermediate  stages  between  the  large  and  the  small 

'■   varieties. 

The  cold  area  gave  us  Astropecten  tenuispinus  in 
great  abundance  and  beauty.  The  tangles  sometimes 
came  up  scarlet  with  them,  and  associated  with  this 
species  a  handsome  new  form  of  a  peculiar  leaden 
grey  colour,  and  with  paxillse  arranged  on  the 
dorsal  surface  of  the  disk  in  the  form  of  a  rosette,  or 
the  petaloid  ambulacra  of  a  Clypeaster.     Astropecten 


^.^ 


122 


THE  DEPTHS  OF  THE  SEA. 


[chap.  III. 


arcticus,  Sars,  was  met  with  sparingly  in  some  of  the 
deeper  dredgings.  The  known  northern  species  of 
Archaster  were  abundant  and  of  large  size;  A. 
parellii,  D.  and  K.,  passing  into  comparatively  shah 
low  water;  and  A.  andromeda  abundant  at  greater 
depths. 


FrG.  17. — Archaster  bifrons,  Wyvitj.e  Thomson.    Dorsiil  aspect.     Three-fourths  of  the  natural 

size.     (No.  .57.) 


At  Stations  57  and  58,  and  at  various  others  in 
the  cold  area  we  took  many  specimens  of  a  fine 
Archaster  (Fig.  17)  with  a  double  row  of  large 
square  marginal  plates  giving  the  edges  a  thickened 
square-cut    appearance    like    those   of    Ctenodiscns; 


t 


,AP,  III.]         THE  CRUISES  OF  THE  'PORCUPINE:  123 

ich  marginal  plate  covered  with  miliary  grains, 
lid  with  a  prominent  rigid  central   spine.      This  is 

large  form,  one  of  our  most  striking  additions  to 
:ie  tale  of  known  species.  It  measures  120  mm.  from 
^p  to  ti]3  of  the  arms  across  the  disk.  The  colour 
i  a  rich  cream,  or  various  shades  of  light  rose. 

Ctenodiscus  crisj^atus  occurred  rarely  and  of  rather 
mall  size,  not  more  than  25  mm.  across.     Nearly 

ery  haul  brought  up  small  specimens  of  Aster- 
canthion  mulleri,  M.  Sars,  and  specimens  of  all  sizes 
f  Cribrella  sanguinolenta,  O.  P.  MtJLLEii. 

The  distribution  of  Ophiuoridea  was  altogether 
ew  to  a  British  dredger.  By  far  the  most  abundant 
)rm  in  moderate  depths  was  Amphiura  abyssicola, 
\L  Sars,  a  species  hitherto  unknown  in  the  British 
eas ;  and  at  greater  depths  this  species  was  associated 
n  about    equal  numbers  with    OpMocten  sericeum, 

y'ORBES. 

Everywhere  Ophiacantha  spimilosa,  M.  and  T., 
tibounds,  and  the  common  Ophioglypha  lacertosa  of 
jihallow  water  is  replaced  by  O.  sai^sii,  Lutken, 
f\a\Q  Ophiopholis  aculeata,  O.  F.  MIjller,  loves  to 
lestle  among  the  branches  of  corals  and  stony 
polyzoa.  In  such  characteristic  cold  area  dredg- 
ngs  as  Stations  54,  55,  57,  and  64,  we  find  the 
:wo  species  of  OpMoscolex,  O.  purpurea^  D.  and 
K.,  and  O.  glacialis,  M.  and  T. ;  the  former  in 
some  places  in  great  abundance,  and  the  latter 
fnuch  more  scarce.  Both  species  are  new  to  the 
British  area,  and  two  very  remarkable  forms  which 
accompany  them  are  new  to  science.  One  of  these 
is  a  very  large  ophiurid  with  thick  arms,  up- 
ivards  of  three  decimetres  long,  and  a  large  soft  disk 


J* 


1 24  THE  DEPTHS  OF  THE  SEA.  [chap.  m. 

resembling  that  of  Ophiomyxa,  to  which  genus  it 
seems  to  be  allied.  Tlie  specimens  which  have  been 
hitherto  procured  are  scarcely  sufficiently  perfect  to 
allow  of  its  being  thoroughly  worked  out.  The  other 
is  a  large  handsome  species  of  Ljungmans  genus 
Ophiopus.  The  plates  covering  the  disk  are  small  and 
obscure,  and  partly  masked  by  a  netted  membrane. 
In  moderate  depths  AmpJdura  balli,  Thompson,  was 
common,  and  we  now  and  then  dredged  a  stray 
example  of  the  beautiful  little  Ophiopeltis  securigerciy  , 
D.  and  K.,  lately  added  to  the  Shetland  fauna  by  ! 
the  Rev.  A.  Merle  Norman. 

It  was  a  matter  of  some  surprise  to  us  as  well  as  \ 
of  great  pleasure  to  bring  up  in  many  of  our  cold  | 
area  hauls  considerable  numbers  of  the  handsomest 
of    the    northern  free   crinoids,   Antedon  escrichtii 
So  far  as  I  am  aware,  this  species  has  not  hitherto 
been  met  with  in  the  Scandinavian  or  Spitzbergen 
seas ;   all  our  museum  specimens  come  from  Green 
land  or  Labrador.     This  is  also  the  case  with  Cteno 
discus  crisp atus.     In  neither  instance  do  the  speci-  i 
mens  from  the  north  of  Scotland  appear  to  be  quite  | 
so  large    as    those   from   Greenland.      One   or  two  \ 
hauls  in  moderate  water  gave  us  abundant  examples  I 
of  Antedon  celticus,  Barrett,  a  form  still  more  com-  f 
mon  however  in  the  Minch ;  and  almost  every  haul  j 
we  found  a  broken  specimen  or  some  fragments  of  | 
Antedon  sarsii.  j 

Once  or  twice  we  found  a  fragment  of  the  stem  of  * 
Hhizocrinus,  but  singularly  enough  no  living  specimen  i 
of  this  interesting  little  crinoid  rewarded  us  from  the 
cold  water,  although   our  conclusion   seemed  to  be 
just,  that  the  Arctic  indraught  sets  into  the  Fseroe 


I  A?.  III.]  THE  CRUISES  OF  THE  *  PORCUPINE:  125 

Ihannel  directly  from  the  seas  of  the  Loffotens  where 

abounds. 

We  dredged  many  Holothurise ;  notably  everywhere 
!|elow  200  or  300  fathoms  the  delicate  little  Echino- 
\icumis  typica,  M.  Saks;  and  Psolus  squamatus, 
LOREN,  which  does  not  seem  however  to  be  common, 
hjough  we  dredged  it  in  great  profusion  on  one  occa- 
lon  in  the  '  Lightning,'  its  white  scaly  disks  showing 
jut  against  the  smooth  black  pebbles  of  Tseroe  basalt 
p  which  they  were  attached.  Holothuria  ecalcarea, 
L-RS,  was  met  with  occasionally,  and  formed  another 


Fig.  1%.—Eusirus  cuspidalus,  Kkoyeb.    (No.  56.) 

nteresting  addition  to  the  British  fauna.  It  always 
lad  a  peculiar  effect  coming  up  among  a  number  of 
nuch  smaller  and  more  delicate  things,  like  a  massive 
jrerman  sausage  twenty  or  thirty  centimetres  long. 

In  the  characteristic  hauls  in  the  cold  area  we  met 
iv^ith  some  very  interesting  crustaceans,  one  or  two  of 
.vhich  I  j&gure  as  they  are  highly  suggestive  of  the 
iource  of  the  cold  water.  They  are  some  of  the 
gigantic  forms  of  amphipoda  and  isopoda  of  the 
A-rctic  sea. 


126 


THE  DEPTHS  OF  THE  SEA. 


[chap.  III.! 


Uuswus   cuspidatus,  Kroyer    (Fig.  18),  had  pre-i 
viously  been  known  only  in  the  Greenland  sea,  and! 


Fig.  19.—Caprella  spmosissma,  Norman,     Twice  the  natural  size.     (No.  5t).) 


the  genus  was  represented  for  the  seas  of  Britain  by 
an  imperfect  example  of  another  species. 

rig.  19  is  a  large  and  hitherto  unknown  species  of 


HAP.  III.]         THE  CRUISES  OF  THE  'PORCUPINE:  127 

he  genus  Caprella,  the  odd-looking  group  of  skeleton 
hrimps  which  fix  themselves  by  their  hind  elaspers, 
isually  in  this  locality  to  branching  sponges,  and  wave 
heir  gaunt  grotesque  bodies  about  in  the  water. 

^ga  nasuta,  Norman  (Fig.  20),  is  another  new 
pecies,  one  of  the  '  normal '  isopods.  Much  larger 
pecimens  of  this  curious  genus  are  however  known 
n  the  British  coasts,  usually  semi-parasitical  on  large 
Lshes. 

Arcturus  baffini,  Sabine  (Eig.  21),  is  another  of 
he  4sopoda  norma lia' — normal  to  a  certain  extent  in 
ts  structure,  but  very  peculiar  in  its  appearance  and 


Vui.  20.—yEi/a  ikusuta,  Norman.     Slightly  enlaiged.     (No.  55. 

abits.  Arcturus  has,  like  Caprella,  the  habit  of 
linging  to  some  foreign  body  by  its  elaspers,  and 
taring  up  the  anterior  part  of  its  body  in  a  queer 
lanner ;  but  it  has  in  addition  a  pair  of  enormously 
eveloped  antennae,  and  to  these  the  young  cling  by 
iieir  elaspers,  and  range  themselves  along  like  a 
auple  of  living  fringes.  Idotea  {Arcturus)  baffini 
as  first  described  in  the  Appendix  to  Captain  Parry's 
)urth  voyage.  This,  or  a  nearly  allied  species, 
^ems  to  occur  also  in  the  Antarctic  seas.  Sir  James 
lark  Ross  remarks,'    that  in  dredging  at  a  depth 

1  A  Voyage  of  Discovery  and  Kesearch,  vol.  i.  p.  202. 


128 


THE  DEPTHS  OF  THE  SEA. 


[chap. 


III. 


of  270  fathoms,  lat.  72  31  S.,  long.  173°  39  R, 
**  corallines,  flustrse,  and  a  variety  of  marine  inverte- 
brate animals  came  up  in  the  net,  showing  an  abun- 
dance and  great  variety  of  animal  life.  Amongst 
them  I  detected  two  species  of  Pycnogonum,  Idotea\ 
haffini,   hitherto   considered   peculiar   to   the   Arcti(3' 


Fig.  21. — Jrc^t/rttsZxy^ni,  Sabine.    About  the  natural  size.    (No.  50.) 


seas  " — and  some  other  forms.  The  figure  represents 
Arcturus  baffini  and  a  few  of  its  progeny,  whicli 
however  have  got  somewhat  into  disorder.  The 
nursery  arrangements  are  usually  much  more  regular. 
One  or  two  species  of  the  singular  marine  arachnida 
of  the   genus   NympJion,  of  a  very  large  size,  were' 


iiAP.  III.]  TtlE  CRUISES  OF  THE  'PORCUPINE: 


129 


jrequently  entangled  in  large  numbers  on  the  loose 
Lamp.  This  group  seems  to  be  specially  characteristic 
|f  the  sea  at  an  arctic  temperature.  They  are  re- 
lorted  of  almost  incredible  size,  thirty  centimetres  or 
b  across,  from  the  late  German  and  Swedish  polar 
expeditions,  and  they   have   also   been  found   enor- 


Fig.  22. — Nymphon  njtyxsni-vm,  Kokma'S.     Sliglitlj- enlargerl     (No.  56.) 


ously  large  in  deep  water  in  the  antarctic  regions, 
bey  often  come  up  clinging  to  the  sounding  line. 
The  MoUusca,  which  in  the  preceding  cruises 
mally  constituted  the  principal  results  of  the 
edging,  were  here  quite  subordinate  as  regards 
)th    number    and   variety   to   the   groups    already 


K 


130  THE  DEPTHS  OF  THE  SEA.  [chap.  hi. 

mentioned;  and  the  difference  between  the  moUuscan 
fauna  of  the  cold  and  that  of  the  warm  area  was  not 
by  any  means  so  great  as  that  shown  in  other  groups. 
One  of  the  most  interesting  types  which  we  met  with 
was  Terehratula  septata,  Philippi  =  T.  septigera, 
LovEN,  a  brachiopod  found  living  at  Station  65  in 
the  Shetland  Channel,  at  a  depth  of  345  fathoms, 
and  a  bottom-temperature  of  — 1°*  IC.  A  variety  of 
this  species,  from  the  Pliocene  beds  of  Messina,  hasj 
been  described  and  figured  by  Professor  Seguenza' 
under  the  name  of  IValdheimia  peloritana  ;  and  it  is| 
clearly  the  same  as  the  Waldheimia  floridana,  foundi 
in  the  Gulf  of  Mexico  by  De  Pourtales,  which  ou 
own  numerous  specimens  so  considerably  exceed  i 
size  as  to  show  that  its  more  congenial  home  is  ii 
frigid  water. 

Only  a  small  number  of  Pishes  were  procured,  bd 
their  scarcity  may  probably  have  been  due  to  im 
unsuitableness  of  the   dredge  as  a  means  for  theii 
capture.     The  few  species  taken  were  placed  in  th^ 
hands  of  Mr.  Couch  of  Polperro  by  Mr.  Loughrin 
and  were  examined  by  him  after  our  return.    The  lis,, 
includes  a  new  generic  form  intermediate  betweeil 
Chimcera  and  Macrourus,  which  was  brought  up  fronj 
a  depth  of  540  fathoms  in  the  cold  area ;  a  new  specie 
of  a  genus  allied  to  Zeus  ;  a  new  Gadus  approachiii{| 
the  common  Whiting;    a  new  species  of    OpMdion^ 
a  species  of  a  new  genus  near  Cyclopterus ;  Blennin 
fasciatus^  Bloch,  new  to  Britain ;  Ammodytes  siculus 
a  fine  new  S err  amis  ;  and  a  new  Syngnathus. 

Death  put  an  end  to  the  labours  of  the  Vetera" 
Cornish  naturalist  while  he  was  preparing  descrip 
tions  and  figures  of  our  new  species.     He  died  full  c 


HAP.  HI.]  THE  CRUISES  OF  THE  'PORCUPINE:  131 

ears  and  work,  and  this  last  task,  on  which  he  had 
tered  with  keen  interest,  must  be  finished  by  other 
ands. 

It  will  be  seen  that  the  bottom  temperature  of  the 

Id  area,  at   500  fathoms,  does  not  differ  by  more 

an  two  or  three  degrees  from  that  of  the  warm 

ea,  at  depths  beyond  1,500  fathoms.      It  seems,  in 

ct,  as  Dr.  Carpenter  has  well  pointed  out,  as  if  all 

le  extreme  climatal  conditions  which,  in  the  deep 

■    ater  of  the  Atlantic  are  extended  over  a  vertical 

[stance  of  two  or  three  miles,  are  here  compressed, 

ithout  greatly  altering  their  proportions,  into  the 

)mpass  of  half  a  mile.     We  have  the  same  surface 

iper-heating  and  rapid  fall  for  the  first  short  dis- 

mce ;  the  same  hump  on  the  curves,  indicating  the 

resence  of  a  layer  of  water  heated  by  some  other 

luse  than  direct  solar  radiation;  the  same  rapid  fall 

irough  a  '  stratum  of  intermixture;'  and,  finally, 

^T  le  same  long  excessively  slow  depression  through  a 

'     ;ep  bottom  bed  of  cold  water  nearly  at  a  uniform 

'     mperature. 

As  might  be  anticipated,  if  the  view  be  correct 
I  lat  arctic  conditions  are  in  a  broad  sense  con- 
i  ^  auous  throughout  the  abyssal  regions  of  the  sea,  a 
I  rge  number  of  the  inhabitants  of  the  '  cold  area '  are 
i  <immon  to  the  deep  water  off  Kockall  and  as  far  south 
i  i  the  coast  of  Portugal ;  but  the  fauna  of  the  Paeroe 
I  (lannel  includes  besides  these  generally  distributed 
i  Irms,  an  assemblage  of  species— for  example  the 
Irge  crustaceans  and  arachnida  and  some  of  the  star- 
i  iihes — which  are  not  only  generally  characteristic  of 
i  iigid  conditions,  but  specially  of  that  part  of  the 
ctic  province  represented  by  the  seas  of  Spitzbergen, 

k2 


132 


THE  DEPTHS  OF  THE  SEA. 


[chap.  III. 


Greenland,  and  Loffoten.  There  can  be  little  doubt 
that  this  especially  arctic  character  of  the  fauna  is 
maintained  by  the  continual  migration  of  arctic 
species  along  with  the  arctic  current  indicated  by 
the  depressions  in  the  lines  of  equal  temperature. 
Many  species  characteristic  of  the  '  cold  area '  were 
not  met  with  beyond  its  limits,  owing  doubtless  to 
the  entire  banking  in  and  disappearance  of  the  cold 
water,  and  the  obliteration  of  the  arctic  current 
as  such  at  the  western  opening  of  the  channel 
between  the  Paeroe  banks  and  the  Hebrides. 


THE    GOVKRNOR'S    HOUSE,    THORSHAVN. 


AP.  III.]  THE  CRUISES  OF  THE  '  rORCUriNE:  133 


i  APPENDIX  A. 

,Oj/icial  Documents  and  Official  Accounts  of  Preliminary  Pro- 
!  ceedings  in  connection  with  the  Explorations  in  H.M.  Sur- 
veying-vessel 'Porcupine,'  during  the  Bummer  of  1869. — 
I  Extracts  from  the  Minutes  of  the  Council  of  the  Royal  Society, 
'  setting  fm^th  the  origin  of  the  '  Porcupine '  Exjjcdition,  and 
the  objects  which  it  was  designed  to  carry  out : — 

January  21,  1869. 

The  Preliminary  Report  of  the  Dredging  Operations  conducted 
by  Drs.  Carpenter  and  Wyville  Tliomson  (in  the  '  Lightning') 
liaving  heen  considered,  it  was 

liesolved, — That,  looking  to  the  valuable  results  obtained  from 
these  Marine  Researches,  restricted  in  scope  as  they  have 
been  in  a  first  trial,  the  President  and  Council  consider  it 
most  desirable,  with  a  view  to  the  advancement  of  Zoology 
and  other  branches  of  science,  that  the  exploration  should 
be  renewed  in  the  course  of  the  ensuing  summer,  and 
carried  over  a  wider  area ;  and  that  the  aid  of  Her 
Majesty's  Government,  so  liberally  afforded  last  year,  be 
again  requested  in  furtherance  of  the  undertaking. 

Resolved, — That  a  Committee  be  appointed  to  report  to  the 
Council  on  the  measures  it  will  be  advisable  to  take  in 
order  to  carry  the  foregoing  resolution  most  advantageously 
into  effect  The  Committee  to  consist  of  the  President 
and  Officers,  with  Dr.  Carpenter,  Mr.  Gwyn  Jeffreys,  and 
Captain  Richards. 

February  18,  1869. 
Read   the  following   Report   of  the    Committee   en   Marine 
Researches  : — 


134  THE  DEPTHS  OF  THE  SEA,  [chap.  hi. 

"The  Committee  appointed  by  the  Council  on  the  21st  of 
January,  to  consider  the  measures  advisable  for  the  further  pro- 
secution of  Kesearches  into  the  Physical  and  Biological  Condi- 
tions of  the  Deep  Sea  in  the  neighbourhood  of  the  British  Coast, 
beg  leave  to  Eeport  as  follows : — 

"  The  results  obtained  by  the  Dredgings  and  Temperature- 
Soundings  carried  on  during  the  brief  Cruise  of  H.M.S.  '  Light- 
ning' in  August  and  September,  1868,  taken  in  connection  with 
those  of  the  Dredgings  recently  prosecuted  under  the  direction 
of  the  Governments  of  Sweden  and  of  the  United  States,  and 
with  the  remarkable  Temperature-Soundings  of  Captain  Short- 
land  in  the  Arabian  Gulf,  have  conclusively  shown — 

"1.  That  the  Ocean-bottom,  at  depths  of  500  fathoms  or  more, 
presents  a  vast  field  for  research,  of  which  the  systematic 
exploration  can  scarcely  fail  to  yield  results  of  the  highest 
interest  and  importance,  in  regard  alike  to  Physical,  Biological, 
and  Geological  Science. 

"  2.  That  the  prosecution  of  such  a  systematic  exploration  is 
altogether  beyond  the  reach  of  private  enterprise,  requiring 
means  and  appliances  which  can  only  be  furnished  by  Govern- 
ment. 

"  It  may  be  hoped  that  Her  Majesty's  Government  may  be 
induced  at  some  future  time  to  consider  this  work  as  one  of  the 
special  duties  of  the  British  N"avy;  which  possesses,  in  the 
world-wide  distribution  of  its  Ships,  far  greater  opportunities  for 
such  researches  than  the  Navy  of  any  other  country. 

"At  present,  however,  the  Committee  consider  it  desirable  that 
the  Royal  Society  should  represent  to  Her  Majesty's  Government 
the  importance  of  at  once  following  up  the  suggestions  appended 
to  Dr.  Carpenter's  '  Preliminary  Report '  of  the  Cruise  of  the 
'  Lightning,'  by  instituting,  during  the  coming  season,  a  detailed 
survey  of  the  deeper  part  of  the  Ocean-bottom  between  the 
North  of  Scotland  and  the  Fseroe  Islands,  and  by  extending  that 
survey  in  both  a  N.E.  and  a  S.W.  direction,  so  as  thoroughly  to 
investigate  the  Physical  and  the  Biological  conditions  of  the  two 
Submarine  Provinces  included  in  that  area,  which  are  character- 
ized by  a  strongly  marked  contrast  in  Climate,  with  a  correspond- 


CHAP.  Ill]  THE  CRUISES  OF  THE  ' FORGUFINE:  135 

ing  dissimilarity  in  Animal  Life,  and   to   trace  this  climatic 
dissimilarity  to  its  source ;  as  well  as  to  carry  down  the  like 
survey  to  depths  much  greater  than  have  been  yet  explored  by 
the  Dredge. 
"  This,  it  is  believed,  can  be  accomplished  without  difficulty 
•    (unless  the  weather  should  prove  extraordinarily  unpropitious) 
by  the  employment  of  a  suitable  vessel,  provided  with  the 
requisite  appliances,  between  the  middle  of  May  and  the  middle 
of  September,    The  Ship  should  be  of  sufficient  size  to  furnish  a. 
Crew  of  which  each  *  watch '  could  carry  on  the  work  con- 
tinuously without  undue  fatigue,  so  as  to  take  the  fullest  advan- 
tage of  calm  weather  and  long  summer  days ;  and  should  also 
I   provide  adequate  accommodation  for  the  study  of  the  specimens 
-   when  freshly  obtained,  which  should  be  one  of  the  primary 
objects  of  the  Expedition.     As  there  would  be  no  occasion  to 
extend  the  Survey  to  a  greater  distance  than  (at  the  most)  400 
miles  from  land,  no  difficulty  would  be  experienced  in  obtaining 
the  supplies  necessary  for  such  a  four  months'  cruise,  by  running 
from  time  to  time  to  the  port  that  might  be  nearest     Thus, 
,   supposing  that  the  Ship  took  its  departure  from  Cork  or  Galway, 
;   and  proceeded  first  to  the  channel  between  the  British  Isles  and 
i   Rockall  Bank,  where  depths  of  from  1,000  to  1,300  fathoms  are 
i    known  to  exist,  the  Dredgings  and  Temperature-Soundings  could 
\  be  proceeded  with  in  a  northerly  direction,  until  it  would  be 
convenient  to  make  Stornoway.     Taking  a  fresh  departure  from 
that  port,  the  exploration  miglit  then  be  carried  on  over  the  area 
;  to  the  N.W.  of  the  Hebrides,  in  which  the  more  moderate 
depths  (from  500  to  600  fathoms)  would  afford  greater  facility  for 
.   the  detailed  survey  of  that  part  of  the  Ocean-bottom  on  which  a 
j   Cretaceous  deposit  is  in  progress — the  Fauna  of  this  area  having 
!  been  shown  by  the  •  Lightning '  researches  to  present  features  of 
most  especial  interest,  while  the  careful  study  of  the  deposit 
may  be  expected  to  elucidate  many  phenomena  as  yet  unex- 
!  plained  which  are  presented  by  the  ancient  Chalk  Formation.     A 
month  or  six  weeks  would  probably  be  required  for  this  part  of 
the  Survey,  at  the  end  of  which  time  the  vessel  might  again  run 
to   Stornoway  for  supplies.     The  area  to  the  N.  and  N.E.  of 


136  THE  DEPTHS  OF  THE  SEA.  [chap.  hi. 

Lewis  sliould  then  be  worked  in  the  like  careful  manner ;  and  as 
the  'cold  area'  would  here  be  encountered,  special  attention 
should  be  given  to  the  determination  of  its  boundaries,  and  of 
the  sources  of  its  climatic  peculiarity.  These  would  probably 
require  the  extension  of  the  survey  for  some  distance  in  a  N.E. 
direction,  which  would  carry  the  vessel  into  the  neighbourhood 
of  the  Shetland  Isles ;  and  Lerwick  would  then  be  a  suitable 
port  for  supplies.  Whatever  time  might  then  remain  would  be 
advantageously  employed  in  dredging  at  such  a  distance  round 
the  Shetlands  as  would  give  depths  of  from  250  to  400  fathoms, 
Mr.  Gwyn  Jeffreys'  dredgings  in  that  locality  having  been  limited 
to  200  fathoms. 

"  The  Natural-History  work  of  such  an  Expedition  should  be 
prosecuted  under  the  direction  of  a  Chief  (who  need  not,  how- 
ever, be  the  same  throughout),  aided  by  two  competent  Assistants 
(to  be  provided  by  the  Royal  Society),  who  should  be  engaged 
for  the  whole  Cruise.  Mr.  Gwyn  Jeffreys  is  ready  to  take  charge 
of  it  during  the  first  five  or  six  weeks,  say,  to  the  end  of  June, 
when  Professor  Wyville  Thomson  would  be  prepared  to  take  his 
place ;  and  Dr.  Carpenter  would  be  able  to  join  the  Expedition 
early  in  August,  remaining  with  it  to  the  end.  It  would  be  a 
great  advantage  if  the  Surgeon  appointed  to  the  Ship  should 
have  sufficient  knowledge  of  Natural  History,  and  sufficient 
interest  in  the  inquiry,  to  participate  in  the  work. 

"  The  experience  of  the  previous  Expedition  will  furnish 
adequate  guidance  as  to  the  appliances  which  it  would  be 
necessary  to  ask  the  Government  to  provide,  in  case  they  accede 
to  the  present  application. 

"  With  reference  to  the  Scientific  instruments  and  apparatus 
to  be  provided  by  the  Eoyal  Society,  the  Committee  recommend 
that  the  detailed  consideration  of  them  be  referred  to  a  Special 
Committee,  consisting  of  gentlemen  practically  conversant  with 
the  construction  and  working  of  such  instruments/' 

Eesolved, — That  the  Report  now  read  be  received  and  adopted, 
and  that  application  be  made  to  Her  Majesty's  Government 
accordingly. 


Jl 


CHAP.  III.]         THE  CRUISES  OF  THE  '  PORCUPINE:  137 

The  following  Draft  of  a  Letter  to  be  transmitted  by  the  Secre- 
tary to  the  Secretary  of  the  Admiralty  was  approved  : — 

*'  The  Royal  Society,  Burlington  House, 
'' February  IS,  1869. 

"  SiE, — Keferring  to  the  'Preliminary  Eeport'  by  Dr.  Carpenter 
of  the  Eesults  of  the  Deep-Sea  Exploration  carried  on  during  the 
brief  Cruise  of  Her  Majesty's  Steam- vessel  'Lightning'  in 
August  and  September  last,  which  has  already  been  transmitted 
for  the  consideration  of  the  Lords  Commissioners  of  the 
Admiralty — I  am  directed  by  the  President  and  Council  of  the 
Eoyal  Society  to  state  that,  looking  to  the  valuable  information 
obtained  from  these  Marine  Eesearches,  although  comparatively 
restricted  in  duration  and  extent,  they  deem  it  most  desirable, 
in  the  interests  of  Biological  and  Physical  Science,  and  in  no 
small  degree  also  for  the  advancement  of  Hydrographical  know- 
ledge, that  a  fresh  exploration  should  be  entered  upon  in  the 
ensuing  summer,  and  extended  over  a  \\ider  area ;  and  they  now 
desire  earnestly  to  recommend  the  matter  to  the  favourable  con- 
sideration of  My  Lords,  in  the  hope  that  the  aid  of  Her  Majesty's 
Government,  which  was  so  readily  and  liberally  bestowed  last 
year,  may  be  afforded  to  the  undertaking  now  contemplated,  for 
which  such  support  would  be  indispensable. 

"  In  favour  of  the  practicability  and  probable  success  of  the 
proposed  fresh  exploration,  I  am  directed  to  explain  that  the 
objects  to  be  aimed  at,  as  well  as  the  course  to  be  followed  and 
the  measures  to  be  employed  for  their  attainment,  have  mainly 
been  suggested  by  the  observations  made  and  the  experience 
gained  in  the  last  Expedition. 

"  Eurther  information  as  to  the  proposed  exploration  will  be 
found  in  the  Eeport,  herewith  transmitted,  of  a  Committee  to 
whose  consideration  the  subject  was  referred  by  the  Council. 

"  It  is  understood  that  the  requisite  Scientific  Apparatus  and 
the  remuneration  of  the  Assistants  to  be  employed  would  be 
provided  by  the  Eoyal  Society.  With  regard  to  the  appliances 
which  Her  Majesty's  Government  may  be  asked  to  provide,  the 
experience  of  the  previous  Expedition  will  furnish  adequate 
guidance,  w^henever  the  general  scheme  may  be  approve.].     It 


138  THE  DEPTHS  OF  THE  SEA,  (chap.  hi. 

has  appeared  to  the  President  and  Council,  that  if  the  ship  i  | 
required  for  the  proposed  service  could  be   provided  by  the  " 
temporary   employment   of   one   of    Her   Majesty's  Surveying 
Vessels  now  in  commission,  anything  beyond  a  trifling  outlay  on 
the  part  of  the  Government  would  be  rendered  unnecessary. 
"I  remain, 

"  Your  obedient  Servant, 

«  W.  Sharpey,  M.D., 

* '  Thd  Secretary  to  the  Admiralty.  **  *  *  Sec.  U.S." 

Eesolved, — That  a  Committee  be  appointed  to  consider  the 
Scientific  Apparatus  it  will  be  desirable  to  provide  for  the 
proposed  Expedition,  The  Committee  to  consist  of  the 
President  and  Officers,  with  Dr.  Carpenter,  Captain  Eichards, 
Mr.  Siemens,  Dr.  Tyndall,  and  Sir  Charles  Wheatstone, 
with  power  to  add  to  their  number. 

That  a  sum  of  £200  from  the  Government  grant  be  assigned 
to  Dr.  Carpenter  for  the  further  prosecution  of  Eesearches 
into  the  Temperature  and  Zoology  of  the  Deep  Sea. 

March  18,  1869. 
An  oral  communication  was  made  by  the  Hydrographer  to  the 
effect  that  the  Lords  Commissioners  of  the  Admiralty  had 
acceded  to  the  request  conveyed  in  Dr.  Sharpey's  letter  of 
February  18 ;  that  Her  Majesty's  Surveying- vessel  '  Porcupine ' 
had  been  assigned  for  the  service ;  and  that  the  special  equip- 
ment needed  for  its  efficient  performance  was  proceeding  under 
the  direction  of  her  Commander,  Captain  Calver. 


April  15,  1869. 
Head  the  following  letter  from  the  Admiralty : — 


"Admiralty,  March  19,  1869. 
**  Sir, — With  reference  to  previous  correspondence,  I  am  coni- 
manded  by  My  Lords  Commissioners  of  the  Admiralty  to 
acquaint  you  that  Dr.  Carpenter  and  his  Assistants,  who  have 
been  deputed  by  the  Eoyal  Society  to  accompany  the  Expedition 
about  to  be  dispatched  to  the  neighbourhood  of  the  Faeroe  Isles 


I 


CHAP.  HI.]  THI  CRUISES  OF  THE  'PORCUPINE:  139 

for  the  purpose  of  investigating  tlie  bottom  of  the  Ocean  by- 
means  of  deep-sea  soundings,  will  be  entertained  whilst  embarked 
on  board  the  '  Porcupine '  at  the  Government  expense. 

*''  I  am.  Sir, 
*'  Your  obedient  servant, 

"W.  G.  EOMAINE." 
"  The  Presidevi  of  the  Boy  at  Society  y 


Eead  the  following  Eeport : — 

"The  Committee  appointed  Feb.  18,  1869,  to  consider  the 
Scientific  Apparatus  it  will  be  desirable  to  provide  for  the  pro- 
posed Expedition  for  Marine  Eesearches,  beg  leave  to  lay  before 
the  Council  the  following  Eeport : — 

"The  chief  subjects  of  Physical  Enquiry  which  presented 
themselves  as  interesting  on  their  own  account,  or  in  relation  to 
the  existence  of  Life  at  great  depths,  were  as  follows  : — 

"(1)  The  temperature  both  at  the  bottom  and  at  various 
depths  between  that  and  the  surface. 

"(2)  The  nature  and  amount  of  the  dissolved  Gases. 

"  (3)  The  amount  of  Organic  matter  contained  in  the  water, 
and  the  nature  and  amount  of  the  Inorganic  salts. 

"  (4)  The  amount  of  Light  to  be  found  at  great  depths. 

"Among  these  subjects  IJie  Committee  thought  it  desirable  to 
confine  themselves  in  the  first  instance  to  such  as  had  previously 
to  some  extent  been  taken  in  hand,  or  could  pretty  certainly  be 
carried  out. 

"  The  determination  of  Temperatures  has  hitherto  rested 
chiefly  upon  the  registration  of  minimum  Thermometers.  It  is 
obvious  that  the  temperature  registered  by  minimum  thermo- 
meters sunk  to  the  bottom  of  the  sea,  even  if  their  registration 
were  unaffected  by  the  pressure,  would  only  give  the  lowest 
temperature  reached  somewhere  between  top  and  bottom,  not 
necessarily  at  the  bottom  itself.  The  temperatures  at  various 
depths  might  indeed,  provided  they  nowhere  increased  on  going 
deeper,  be  determined  by  a  series  of  minimum  thermometers 
placed  at  different  distances  along  the  line,  though  this  would 


1  40  THE  DEPTHS  OF  THE  SEA.  [chap.  jji. 

involve  considerable  difficulties.  Still,  the  liability  of  the  index 
to  slip,  and  the  probability  that  the  indication  of  the  thermo- 
meters would  be  affected  by  the  great  pressure  to  which  they 
were  exposed,  rendered  it  very  desirable  to  control  their  indica- 
tions by  an  independent  method. 

''  Two  plans  were  proposed  for  this  purpose,  one  by  Sir  Charles 
Wheatstone,  and  one  by  Mr.  Siemens.  Both  plans  involved  the 
employment  of  a  voltaic  current,  excited  by  a  battery  on  deck ; 
and  required  a  cable  for  the  conveyance  of  insulated  wires.  The 
former  plan  depended  upon  the  action  of  an  immersed  Breguet's 
thermometer,  which,  by  an  electro-mechanical  arrangement,  was 
read  by  an  indicating  instrument  placed  on  deck.  The  latter 
plan  made  the  indication  of  temperature  depend  on  the  existence 
of  a  thermal  variation  in  the  electric  resistance  of  a  conducting 
wire.  It  rested  on  the  equalization  of  the  derived  currents  in 
two  perfectly  similar  partial  circuits,  containing  each  a  copper 
wire  running  the  whole  length  of  the  cable,  the  sea,  and  a 
resistance- coil  of  fine  platinum  wire  ;  the  coil  in  the  one  circuit 
being  immersed  in  the  sea  at  the  end  of  the  cable,  and  that  in 
the  other  being  immersed  in  a  vessel  on  deck,  containing  water 
the  temperature  of  which  could  be  regulated  by  the  addition  of 
hot  or  cold  water,  and  determined  by  an  ordinary  thermometer. 

"The  instruments  required  in  Sir  Charles  Wheatstone's  plan 
were  more  expensive,  and  would  take  longer  to  construct ;  and, 
besides,  the  Committee  were  unwilling  to  risk  the  loss  of  a  some- 
what costly  instrument  in  case  the  cable  were  to  break.  On 
these  accounts  they  thought  it  best  to  adopt  the  simpler  plan 
proposed  by  My.  Siemens  ;  and  the  apparatus  required  for  carry- 
ing the  plan  into  execution  is  now  completed,  and  in  use  in  the 
expedition. 

"  Meanwhile  a  plan  had  been  devised  by  Dr.  Miller  for 
obviating  the  effect  of  pressure  on  a  minimum  thermometer, 
without  preventing  access  to  the  stem  for  the  purpose  of  setting 
the  index.  It  consists  in  enclosing  the  bulb  in  an  outer  bulb 
rivetted  on  a  little  way  up  the  stem,  the  interval  between  the 
bulbs  being  partly  filled  with  liquid,  for  the  sake  of  quicker 
conduction.     The  Committee  have  had  a  few  minimum  thermo-  ^ 


CHAP.  HI.]  THE  CRUISES  OF  THE  '  PORCUPINE:  Ul 

meters  constructed  on  this  principle,  which  have  been  found  to 
answer  perfectly.  The  method  is  described  in  a  short  paper 
which  will  be  read  to  the  Society  to-morrow. 

"  For  obtaining  specimens  of  water  from  any  depth  to  which 
the  dredging  extends,  the  Committee  have  procured  an  instru- 
ment constructed  as  to  its  leading  features  on  the  plan  of  that 
described  by  Dr.  Marcet  in  the  Philosophical  Transactions  for 
1819,  and  used  successfully  in  the  earlier  northern  expeditions. 

"Mr.  Gwyn  Jeffreys  is  now  out  on  the  first  Cruise  of  the 
*  Porcupine/  the  vessel  which  the  Admiralty  have  sent  out  for 
the  purpose,  and  is  accompanied  by  Mr.  W.  L.  Carpenter,  B.Sc. 
(son  of  Dr.  Carpenter),  who  undertakes  the  general  execution  of 
the  physical  and  chemical  part  of  the  inquiry.  A  letter  has 
been  received  by  the  President  from  Mr.  Jeffreys,  who  speaks 
highly  of  the  zeal  and  efficiency  of  Mr.  Carpenter.  The  ther- 
mometers protected  according  to  Dr.  Miller's  plan,  and  the 
instrument  for  obtaining  specimens  of  water  from  great  depths, 
have  been  found  to  work  satisfactorily  in  actual  practice.  Mr. 
Siemens'  instrument  was  not  quite  ready  when  the  vessel  started 
on  her  first  Cruise,  and  was  not  on  board  when  the  above  letter 
was  written.  The  gas-analyses  have  been  successfully  carried 
on,  notwithstanding  the  motion  of  the  vessel.  From  a  letter 
subsequently  received  from  Mr.  Carpenter,  it  appears  that  Mr. 
Siemens'  apparatus,  so  far  as  it  has  yet  been  tried,  works  in 
perfect  harmony  with  the  thermometers  protected  according  to 
Dr.  Miller's  plan." 

•'  June  16,  1869." 

Resolved, — That  the  Eeport  now  read  be  received  and  entered 
on  the  Minutes. 


142 


THE  DEPTHS  OF  THE  SEA. 


[chap.  Hi. 


APPENDIX  B. 


Particulars  of  Depth,  Temperature,  and  Position  at  the  various 
Dr edging-stations  of  H.M.S.  'Porcupine'  in  the  Summer 
of  1869 :— 


Number 

Depth  in 

Bottom 

Surface 

1>/^c 

of  Station. 

Fathoms. 

Temperature. 

Temperature. 

r^OSiuiuii. 

1 

370 

9°-  4  a 

12°-  3  C. 

5r5rK 

ir50'W. 

2 

808 

5 

•2 

12 

•3 

51  22 

12  25 

3 

722 

6 

•1 

12 

•5 

51  38 

12  50 

4 

251 

9 

•7 

12 

•0 

51  56 

13  39 

5 

364 

9 

12 

•2 

52     7 

12  52 

6 

90 

10 

•0 

12 

•2 

52  25 

11  40 

7 

159 

10 

•  2 

11 

■8 

52  14 

11  48 

8 

106 

10 

•7 

12 

3 

53  15 

11  51 

9 

165 

9 

•8 

12 

0 

53  16 

12  42 

10 

85 

9 

•7 

12 

5 

53  23 

13  29 

11 

1630 

^ 

— 



_ 

53  24 

15  24 

12 

670 

5 

9 

11 

2 

53  41 

14  17 

13 

208 

9 

8 

12 

0 

53  42 

13  55 

14 

173 

9 

8 

11 

8 

53  49 

13  15 

15 

422 

8 

3 

11 

2 

54     5 

12  17 

16 

816 

4 

2 

11 

7 

54  19 

11  50 

17 

1230 

3 

2 

11  • 

8 

54  28 

11  44 

18 

183 

9 

7 

11 

8 

54  15 

11     9 

19 

1360 

3 

0 

12- 

6 

54  53 

10  56- 

20 

1443 

2 

8 

13- 

0 

55  11 

11  31 

21 

1476 

0 

7 

13  • 

4 

55  40 

12  46 

22 

1263 

2 

y 

13- 

8 

56     8 

13  34 

23 

630 

6 

4 

14- 

0 

56     7 

14  19 

23a 

420 

8- 

0 

13  • 

7 

56  13 

14  18 

24 

109 

8 

0 

14- 

3 

56  26 

14  28 

25 

164 

8- 

1 

13  • 

7 

56  41 

13  39 

III.] 


THE  CRUISES  OF  THE  'PORCUPINE: 


143 


t 

Number 

Depth  in 

Bottom 

Surface, 

Posit''""" 

of  Station. 

Fathoms. 

Temperature. 

Temperature. 

26 

345 

8°-  2  C. 

14°- 1  e. 

56°58'K 

13°  ir  w. 

27 

54 

9 

1 

13 

1 

r  Eockall  \ 
(     Bank,  j 

1  Eockall ) 
t     Bank.  J 

28 

1215 

2 

8 

14 

2 

56  44 

12  52 

29 

1264 

2 

7 

13 

8 

56  34 

12  22 

30 

1380 

2 

8 

13 

3 

56  24 

11  49 

,     31 

1360 

2 

9 

13 

8 

56  15 

11  25 

32 

1320 

3 

0 

13 

3 

56     5 

10  23 

33 

74 

9 

•8 

18 

4 

50  38 

9  27 

34 

75 

9 

8 

18 

9 

49  51 

10  12 

35 

96 

10 

7 

17 

4 

49     7 

10  57 

!     36 

725 

6 

1 

17 

7 

48  50 

11     9 

I     37 

2435 

2 

5 

18 

6 

47  38 

12     8 

i     38 

2090 

2 

4 

17 

•9 

47  39 

11  33 

39 

557 

8 

3 

17 

•2 

49     1 

11  56 

40 

517 

8 

7 

17 

•4 

49     1 

12     5 

41 

584 

8 

1 

17 

4 

49     4 

12  22 

42 

862 

4 

3 

17 

0 

49  12 

12  52 

!  4^ 

1207 

3 

2 

16 

5 

50     1 

12  26 

44 

865 

4 

1 

16 

•2 

50  20 

11  34 

i    45 

458 

8 

9 

15 

9 

51     1 

11  21 

46 

374 

7 

7 

12 

1 

59  23 

7    4 

47 

542 

6 

5 

12 

2 

59  34 

7  18 

48 

540 

_ 

— 

— 

_ 

59  32 

6  59 

49 

475 

7 

4 

12 

•0 

59  43 

7  40 

i    50 

355 

7 

9 

11 

4 

59  54 

7  52 

!    51 

440 

5 

5 

10 

9 

60     6 

8  14 

i    62 

384 

-0 

8 

11 

2 

60  25 

8  10 

!    53 

490 

-1 

1 

11 

2 

60  25 

7  26 

\    54 

363 

^0 

3 

11 

4 

69  56 

6  27     ■ 

55 

605 

-1 

2 

11 

4 

60     4 

6  19 

66 

480 

-0 

7 

11 

4 

60     2 

6  11 

!    57 

632 

-  0 

8 

11 

1 

60  14 

6  17 

i    58 

540 

-0 

6 

10 

6 

60  21 

6  51 

1    59 

580 

- 1 

3 

11 

5 

60  21 

5  41 

i    60 

167 

6 

9 

9 

7 

61     3 

5  58 

61 

114 

7 

2 

10 

2 

62     1 

5  19 

'    62 

125 

7 

0 

9 

8 

61  59 

4  38 

63 

317 

-0-9 

9  -4 

61  57 

4    2 

144 


THE  DEPTHS  OF  THE  SEA. 


Number 

Depth  in 

Bottom 

Surface 

PQgj  +  iriTl 

of  Station. 

Fathoms. 

Temperature. 

Temperature. 

64 

640 

-  r- 1  c. 

9^'  3  C. 

6r2i']sr. 

3°  44'  W 

65 

345 

-1 

•  1 

11 

•  1 

61  10 

2  21 

^Q> 

267 

7 

6 

11 

3 

61  15 

1  44 

67 

64 

9 

5 

11 

0 

60  32 

0  29 

68 

75 

6 

7 

11 

•4 

60  23 

0  33  E. 

69 

67 

6 

5 

12 

0 

60     1 

0  18  E. 

70 

66 

7 

3 

11 

9 

60     4 

0  21 

71 

103 

9 

2 

11 

6 

60  17 

2  53 

72 

76 

9 

4 

11 

3 

60  20 

3     5 

73 

84 

9 

4 

11 

5 

60  29 

3     6 

74 

203 

8 

7 

11 

4 

60  39 

3     9 

75 

250 

5 

5 

10 

8 

60  45 

3     6 

76 

344 

-1 

1 

10 

1 

60  36 

3  58 

77 

560 

-  1 

2 

10 

5 

60  34 

4  40 

78 

290 

5 

3 

11 

2 

60  14 

4  30 

79 

76 

9 

4 

11 

2 

59  44 

4  44 

80 

92 

9 

6 

11 

8 

59  49 

4  42 

81 

142 

9 

5 

11 

8 

59  54 

5     1 

82 

312 

5 

2 

11 

2 

60     0 

5  13 

83 

362 

3 

0 

11 

7 

60     6 

5     8 

84 

155 

9 

5 

11 

4 

59  34 

6  34 

85 

190 

9 

3 

12 

1 

59  40 

6  34 

86 

445 

-  1 

0 

12 

0 

59  48 

6  31 

87 

767 

5 

2 

11 

4 

59  35 

9  11 

88 

705 

5 

9 

12 

0 

59  26 

8  23 

89 

445 

7  •'5 

11 

7 

59  38 

7  46 

90 

458 

7-3 

11-7 

59  41 

7  34 

1 

CHAPTER  IV. 

THE    CRUISES    OF    THE    ^  PORCUPINE  '    {continued). 

From  Shetland  to  Stornoway, — Phosplioresceiice. — The  Echinoihuridce. 
—The  Fauna  of  the  '  Warm  Area.'— End  of  the  Cruise  of  1869. 
Arrangements  for  the  Expedition  of  1870. — From  England  to 
Gibraltar. — Peculiar  Conditions  of  the  Mediterranean. — Return  to 
Cowes. 

Appendix  A. — Extracts  from  the  Minutes  of  Council  of  the  Royal 
Society,  and  other  official  documents  referring  to  the  Cruise  of 
H.M.S.  'Porcupine'  during  the  Summer  of  1870. 

Appendix  B. — Particulars  of  Depth,  Temperature,  and  Position  at 
the  various  Dredging-stations  of  H.M.S.  'Porcupine'  in  the 
Summer  of  1870. 

*^*  Tlie  bracketed  numbers  to  the  woodcuts  in  this  chapter  refer  to  the  dredging- 
stations  on  Plates  IV.  and  V. 

We  left  Lerwick  on  the  31st  of  August,  and  ran 
south-  and  westward,  passing  close  to  Sumburgh 
Head;  Fair  Isle,  of  evil  repute  among  mariners, 
lying  on  the  southern  horizon  like  a  little  grey 
3loud.  The  weather  was  still  very  fine,  and  we 
lad  a  good  tossing  with  scarcely  a  breath  of  wind 
n  the  famous  Roost  of  Sumburgh.  Past  Noma's 
-yrie  on  the  '  Eitful  Head  ; '  past  in  the  falling 
hadows  of  the  autumn  night  the  rocky  Island  of 
I'oula,  still  the  haunt  of  one  or  two  pairs  of  the 
Teat   skua    gull,  Lestris   cataractes,    a    species  fast 

L 


146  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

hastening  to  join  the  dodo  and  the  gair-fowl  among 
the  creatures  of  bygone  times. 

We  now  steered  somewhat  to  the  north  of  west,  and 
early  on  the  1st  of  September  sounded  in  lat.  60°  17', 
long.  2°  53',  at  a  depth  of  103  fathoms,  and  a  bottom 
temperature  of  9° '2  C.  We  were  still  in  the  shallow 
water,  and  had  not  touched  the  arctic  stream.  All 
day  we  slipped  over  the  edge  of  the  plateau,  dredging 
chiefly  well-known  Shetland  forms,  and  the  tempera- 
ture falling  slightly,  reaching  in  the  afternoon  at'  a 
depth  of  203  fathoms,  8°-7  C.  (Station  74).  The  next 
sounding,  about  ten  miles  farther  north,  gave  us  the 
stratum  of  intermixture,  a  temperature  of  5°*5  0.  at  a 
depth  of  250  fathoms.  We  ran  about  thirty  miles  in 
the  night,  and  early  next  morning  dredged  in  the 
frigid  water  again  in  lat.  60°  36'  N.,  long.  3°  58'  N.,  at 
a  depth  of  344  fathoms,  with  a  bottom  temperature  of 
~1°*1  C,  the  temperature  at  the  surface  being  10°'l  C. 
Five-and-twenty  miles  to  the  westward,  we  sounded 
again  at  noon  of  the  same  day  at  560  fathoms,  with 

-r-2C. 

In  these  two  or  three  last  cold  dredgings  the 
character  of  the  bottom  was  much  the  same  —gravel 
of  the  older  rocks,  and  clay.  The  preponderance 
of  echinoderms  and  sponges  was  again  remarkable, 
and  the  paucity  of  mollusca,  though  in  this  region 
we  took  a  single  specimen  of  a  moUusk  which 
seemed  to  be  greatly  out  of  its  latitude.  This  was  a 
pretty  little  brachiopod,  Flatydiacm  omioides,  Sacchi 
(Morrisia,  Davidson),  hitherto  found  only  in  the 
Mediterranean.  The  size  of  this  specimen  greatly 
exceeded  that  of  Mediterranean  examples  of  the 
same   species    a  singular  circumstance  which  leads 


CHAP.  IV.]  TEE  CRUISES  OF  THE  ' PORCUFINE:  147 

our  friend  Mr.  Gwyn  Jeffreys  to  the  somewhat 
hazardous  presumption  that  **its  original  home  is 
in  the  boreal,  perhaps  even  in  the  arctic  region." 

Two  very  peculiar  little  sponges  were  met  with  here 
rather  frequently  sticking  to  stones.  A  short  smooth 
column,  about  20  mm.  in  height,  is  surmounted  in 
one  species,  which  must  I  think  be  identified  with 
Thecophora  semisuberites,  OscAU  Schmidt,  by  a  soft 


Ff«.  2-i.— Thecophora  semisuherites,  Ohvas,  Schmidt.     Twice  the  iiiitaral  size.    (No  76.) 

pad  of  spongy  matter,  with  one  or  two  projecting 
tubes  with  oscula  in  the  centre.  The  other,  which  I 
shall  call  Thecophora  ibla  (Fig.  24),  from  its  resem- 
blance to  the  cirripede  of  that  name,  ends  in  a  scaly 
cone  with  a  single  osculum  in  the  middle.  The  outer 
wall  of  the  column  in  both  forms  is  firm  and  glossy, 
under  the  microscope  composed  of  closely-packed 
sheaves  of  needle-shaped  spicules  with  their  termi- 
nation blunt  and  slightly  bulbous.     The  sheaves  are 

L  2 


148  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

arranged  vertically,  and  this  peculiar  tissue  forms  a 
complete  sheatli  surrounding  a  pulpy  mass  of  gra- 
nular horny  and  sarcodic  matter  which  fills  the  in- 
terior. In  this  inner  spongy  substance  sheaves  of 
similarly-shaped  spicules  are  likewise  arranged  ver- 
tically, but  much  more  loosely ;  and  the  projecting 
scales  forming  the  head  of  Thecophora  ibla  are  formed 
by  the  projecting  ends  of  such  sheaves.  Among 
echinoderms,  OpJiiacantha  spimilosa  was  one  of  the 


Fig.  'ZA.—Thecophwa  ibla,  Wyvii-lk  Thomson.     Twice  the  natural  size.    (No.  7C,.) 

prevailing  forms,  and  we  were  greatly  struck  with 
the  brilliancy  of  its  phosphorescence.  Some  of 
these  hauls  were  taken  late  in  the  evening,  and  the 
tangles  were  sprinkled  over  with  stars  of  the  most 
brilliant  uranium  green ;  little  stars,  for  the  phos- 
phorescent light  was  much  more  vivid  in  the  younger 
and  smaller  individuals.  The  light  was  not  constant, 
nor  continuous  all  over  the  star,  but  sometimes  it 
struck  out  a  line  of  fire  all  round  the  disk,  flashing, 


CHAP.  IV.]  THE  CRUISES  OF  THE  'PORCUPINE:  149 

or  one  might  rather  say  glowinc^,  up  to  the  centre; 
then  that  would  fade,  and  a  defined  patch,  a  centi- 
metre or  so  long,  break  out  in  the  middle  of  an  arm 
and  travel  slowly  out  to  the  point,  or  the  whole  five 
rays  would  light  up  at  the  ends  and  spread  the  fire 
inwards.     Very  young  Ophiacanthce,  only  lately  rid 
of  their  '  plutei,'  shone  very  brightly.     It  is  difficult 
to   doubt  that  in  a  sea  swarming  with  predaceous 
crustaceans,  such  as  active  species  of  Dorynchus  and 
Munida    with    great    bright    eyes,    phosphorescence 
must  be   a  fatal   gift.     We   had   another   gorgeous 
display  of  luminosity  during  this   cruise.     Coming 
down    the    Sound   of    Skye   from    Loch    Torridon, 
on  our  return,  we   dredged  in  about  100  fathoms, 
and    the   dredge   came    up    tangled   with    the    long 
pink  stems  of  the  singular  sea-pen  Tavonaria  qua- 
drangularis.     Every  one  of  these  was  embraced  and 
strangled  by  the  twining  arms  of  Aster  onyx  lovSni, 
and  the  round  soft  bodies  of  the  star-fishes  hung  from 
them  like  plump  ripe  fruit.     The   Pavonarice  were 
resplendent  with  a  pale  lilac  phosphorescence   like 
the  flame  of  cyanogen  gas ;  not  scintillating  like  the 
green  light  of  Ophiacantha,  but  almost  constant,  some- 
times flashing  out  at  one  point  more  brightly  and 
then  dying  gradually  into  comparative  dimness,  but 
always  sufficiently  bright  to  make  every  portion  of  a 
stem  caught  in  the  tangles  or  sticking  to  the  ropes 
distinctly  visible.     From  the  number  of  specimens  of 
Favonaria  brought  up  at  one  haul  we  had  evidently 
passed  over  a  forest  of  them.    The  stems  were  a  metre 
long,  fringed  with  hundreds  of  polyps. 

OpJiiocten  sericeum,  Forbes,  and  OpMoscolex  pur- 
purea^ D.  and  K.,  were  likewise  very  common,  and 


15a 


THE  DEPTHS  OF  THE  SEA. 


[chap.  IV. 


in  sand  patches,  Ophioglypha  sarsii,  Lutken.  The 
most  abundant  asterid  was  Asteropecten  tenuispu 
nus,  always  a  marked  object  from  its  bright  red 
colour — with  here  and  there  an  example  of  Archaster 
andromeda  and  Fteraster  miUtaris.  Every  haul 
brought  up  several  specimens  of  the  so-called  large 


Yn-i.^o.—Archaste.rvexiUifer,Vf\\iiA.T,  Thomson.     One-third  the  natural  sire.    (No.Tfi) 


form  of  Echinus  norvegicus,  here  of  a  pale  colour, 
somewhat  conical,  and  looking  suspiciously  like 
small  forms  of  JE.  jlemingii. 

Along  with  one  or  two  specimens  of  Archaster 
andromeda^  we  took  at  Station  76  an  exceedingly 
beautiful  Archaster  (Pig.  25),  certainly  by  far  the 
finest  species  yet  dredged  in  the  Northern  Seas. 

The  arms  are  flattened,  somewhat  square  in  section 


CHAP.  IV.]  THE  CRUISES  OF  THE  '  FORCUFJI^^E'  1  51 

owing  to  the  position  and  size  of  the  marginal  plates, 
which  run  up  nearly  vertically  from  the  side  of  the 
unusually  wide  amhulacral  groove  till  they  meet  the 
edge  of  the  perisoni  of  the  dorsal  surface.  The  mar- 
ginal plates  are  thickly  covered  with  rounded  scales 
and  bear  three  rows  of  spines — one  at  the  upper  edge 
(and  this  series  in  combination  form  a  fringe  round 
the  dorsal  surface  of  the  star-fish),  one  near  the  centre, 
and  one  a  little  farther  down  towards  the  ventral 
edge.  The  amhulacral  groove  is  bordered  by  ob- 
liqaely  placed  combs  of  spines,  short  towards  the 
apex  and  centre  of  the  arm,  but  becoming  longer 
towards  its  base,  and  forming  at  the  re-entering 
angles  between  the  amhulacral  grooves  large  sin- 
gularly beautiful  pads ;  each  plate  bearing  a  double 
row  of  spines,  and  each  spine  having  a  second  short 
spine  or  scale  on  the  end,  an  arrangement  which 
adds  greatly  to  the  richness  of  the  bordering.  The 
inner  spine  of  each  comb  on  the  side  of  the  amhu- 
lacral groove  is  longer  than  the  others,  and  bears 
on  the  end  a  little  oblong  calcareous  plate  usually 
hanging  from  it  somewhat  obliquely  like  a  flag, 
with  sometimes  a  rudiment  of  a  second  attached  to 
it  in  a  gelatinous  sheath,  which  makes  it  pro- 
bable that  it  is  an  abortive  pedicellaria.  Prom 
this  character,  which  is  one  which  cannot  escape 
observation,  I  have  called  the  species  '  vexillifer.' 
I  know  no  star-fish  in  w^hich  the  amhulacral  grooves 
are  so  wide  and  the  amhulacral  tubes  so  large  in  pro- 
portion to  the  size  of  the  animal  as  in  this  species. 
The  dorsal  perisom  is  closely  covered  with  rosette-like 
paxillse.  The  colour  is  a  pale  rose,  with  a  tinge  of 
buff.     The  amhulacral  tubes,  which  when  the  animal 


152  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

is  living  present  a  very  marked  feature  from  their 
great  size,  are  semi-transparent  and  of  a  pale  pink 
colour. 

We  now  took  a  run  once  more  to  the  southward, 
recrossing  the  boundary  of  the  cold  stream,  and 
sounding  successively  in  290  fathoms,  with  a  bottom 
temperature  of  5°-3  C,  and  in  76  fathoms,  with  a 
temperature  of  9°'4,  practically  the  same  result  as 
in  the  former  case ;  and  in  the  next  four  Stations, 
80,  81,  82,  and  83,  we  repeated  the  operation  in- 
versely, sounding  in  92  fathoms,  with  a  tempera- 
ture of  9°-7  C. ;  in  142,  with  9°-5 ;  in  312,  with  5°-2 ; 
and  in  362,  with  3''-0. 

After  a  run  of  about  sixty  miles  in  a  south-easterly 
direction  nearly  parallel  with  the  lOO-fathom  line,  on 
the  morning  of  Saturday  the  4th  of  September  we 
sounded  in  lat.  59°  34'  jST.,  long.  6°  34'  W.,  with  a 
depth  of  155  fathoms  and  a  temperature  of  9°*5  C. 
Two  other  Stations  after  running  distances  of  six 
and  eight  miles  only  took  us  once  more  over  the 
edge  of  the  bank  and  into  the  cold  river,  the  first 
giving  a  depth  of  190  fathoms,  with  a  temperature  of 
9°*3,  and  the  second  445  fathoms,  and   -  1°*0. 

As  we  were  satisfied  for  the  present  with  our  work 
in  the  cold  area,  and  as  the  next  day  was  the  day  of 
rest,  we  steamed  quietly  westwards  for  about  100 
miles,  past  the  Butt  of  the  Lews  and  beyond  the 
entrance  of  the  channel  to  Station  87,  lat.  59°-35'  N., 
long.  2°  11'  W.,  a  point  nearly  in  the  middle  line  of 
the  deep  water  of  the  channel,  and  consequently  in 
the  axis  of  the  cold  stream,  the  line  in  which  the 
peculiarities  of  the  cold  area  are  most  pronounced. 
Here  a  sounding  gave  us  a  depth  of  767  fathoms  and 


CHAP.  IV.]  THE  CR UISES  OF  THE  '  FORCUflNE:  153 

a  bottom  temperature  of  6°-  2  0.  We  were  thus  in 
the  warm  area,  and  the  dead-cold  water  of  the  cold 
area  lying  fifty  or  sixty  miles  off,  with  the  bottom 
at  a  higher  level,  was  completely  banked  in.  The 
bottom  temperature  here  corresponded  so  closely 
with  that  of  the  same  depth  in  the  Eockall  Channel 
that  apparently  scarcely  a  drop   of  the   Arctic  in- 


FiG.  20.— Zoroaster  fulgtns,  Wtvilljj:  Thomson.     One-third  the  natural  size.    (No.  78.) 

draught  makes  its  escape  in  this  direction.  The 
dredge  here  brought  up  half  a  ton  of  Atlantic 
*  globigerina  ooze,'  a  load  which  tested  its  tackle 
and  the  donkey-engine  to  the  utmost.  The  weight 
of  the  dredge  itself  with  the  weight  attached  was 
8  cwt.,   so  that  altogether  the  burden   reached  not 


154  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

far  short  of  a  ton, ,  and  the  distance  it  had  to  he 
dragged  through  the  water  was  not  much  less  than  a 
mile.  As  was  frequently  the  case  when  these  great 
loads  came  up,  there  were  few  of  the  higher  animal 
forms  in  the  dredge.  The  tangles  brought  up,  how- 
ever, two  or  three  specimens  of  a  very  handsome  star- 
fish, the  type  of  a  new  genus. 

Zoroaster  fulgens  (Fig.  26)  is  a  five-rayed  star-fish, 
250  mm.  from  tip  to  tip  of  the  arms,  which  run  close 
up  to  the  centre  leaving  a  small  disk  not  more  than 
20  mm.  in  diameter.  There  are  four  rows  of  sucking 
feet  in  the  ambulacral  grooves,  a  character  which 
places  the  genus  in  the  first  division  of  the  Asterida, 
along  with  Asteraca7ithion.  The  arms  are  compressed 
laterally,  and  run  up  to  a  central  longitudinal  ridge, 
which  bears  a  row  of  large  pointed  spines  articulated 
to 'a  row  of  projecting  knob-like  ossicles.  From  this 
ridge  bands  of  ossicles  curve  downwards  to  the  edge 
of  the  ambulacral  groove  so  close  together  and  so 
thick  and  solid  that  the  arms  are  continuously  and 
strongly  mailed  over.  The  disk  is  paved  with  large 
calcareous  tubercles  with  articulated  spines;  the  tuber- 
cles and  spines  becoming  larger  towards  the  centre  of 
the  disk.  The  whole  surface  of  the  body  is  covered 
with  long  fine  spines,  with  here  and  there  a  group 
of  pedicellariae  on  short  soft  stalks  attached  to  the 
tops  of  special  spines,  while  a  row  of  such  spines 
bearing  large  groups  of  pedicellariae  runs  along  the 
edges  of  the  ambulacral  grooves.  When  living,  the 
whole  surface  of  the  animal  is  covered  with  a 
quantity  of  glairy  mucus.  The  colour  of  the  perisom 
is  a  magnificent  yellow  scarlet,  but  it  is  very  evan- 
escent,  fading    immediately    in    spirit.      This   is   a 


CHAP.  IT.]  THE  CRUISES  OF  THE  'PORCUFINE:  155 

distinct,  as  well  as  a  very  striking  form.  We  only 
met  with  it  on  this  occasion.  Tlie  skeleton  of  this 
star-fish  at  first  sight  closely  resembles  that  of  some 
species  of  Op1iidlaste7\  for  instance  O.  asperuliis, 
LtJTKEN.  It  is  at  once  distinguished,  however,  by  the 
fundamental  character  of  the  quadruple  row  of  ambu- 
lacral  suckers ;  and  the  texture  of  the  surface  of 
the  star-fish  is  utterly  difPerent.  The  arrangement 
of  the  ossicles  of  the  frame-work  is  perhaps  nearest 
to  that  in  Arthraster  dixoni,  Eoubes,  from  the  lower 
chalk  of  Balcombe  pit  near  Amberley,  Sussex;  but 
the  only  specimen  of  that  species,  now  in  the  British 
Museum,  unfortunately  does  not  show  the  arrange- 
ment of  the  plates  in  the  ambulacral  grooves. 

As  our  coals  were  beginning  to  run  short,  and 
what  remained  were  blowing  off  fast — steaming 
against  rather  a  strong  head  wind — we  thought  it 
prudent  to  retrace  our  steps  slowly  towards  Storno- 
way,  dredging  on  our  way.  Accordingly,  in  the 
afternoon,  we  took  a  haul  in  lat.  59°  26',  N.,  long. 
8°  23'  W.,  with  a  depth  of  705  fathoms,  and  a 
temperature   of    5°*9    C.      Continuing   our    easterly 

;  course  during  the  night,  but  heading  slightly  north- 
wards   so  as    to   come   upon  the  ground  where  we 

I  had  been  previously  so   successful   in   dredging  the 

\  singular  anchoring  sponges,  we  dredged  in  the 
morning  in  lat.  59°  38'  N.,  long.  T  46'  W.,  with  a 
depth  of  445  fathoms  and  a  temperature  of  T'  5  C. 
This  haul  was  not  very  rich,  but  it  yielded  one  speci- 
men of  extraordinary  beauty  and  interest.  As  the 
dredge  was  coming  in  we  got  a  glimpse  from  time  to 
time   of   a   large    scarlet   urchin    in   the   bag.     We 

!  thought   it   was   one  of   the   highly-coloured  forms 


156 


THE  DEPTHS  OF  THE  SEA. 


[chap.  IV, 


of  Echinus  flemingii  of  unusual  size,  and  as  it  was 
blowing  fresh  and  there  was  some  little  difficulty  in 
getting  the  dredge  capsized,  we  gave  little  heed  to 
what  seemed  to  be  an  inevitable  necessity — that  it 
should  be  crushed  to  pieces.  "We  were  somewhat 
surprised,  therefore,  when  it  rolled  out  of  the  bag 
uninjured;  and  our  surprise  increased,  and  was  cer- 


Fio.  27.—Calveria  hystrix,  Wyville  Thomson.     Two'-tliirds  the  natural  size.     iNo.  86.) 


tainly  in  my  case  mingled  with  a  certain  amount  of 
nervousness,  when  it  settled  down  quietly  in  the  form 
of  a  round  red  cake,  and  began  to  pant — a  line  of 
conduct,  to  say  the  least  of  it  very  unusual  in  its 
rigid  undemonstrative  order.  Yet  there  it  was  with 
all  the  ordinary  characters  of  a  sea-urchin,  its  inter- 
ambulacral  areas,  and  its  ambulacral  areas  with  their 


CHAP.  IV.]  THE  CRUISES  OF  THE  '  PORCUPINE:  157 

rows  of  tube  feet,  its  spines,  and  five  sharp  blue  teeth ; 
and  curious  undulations  were  passing  through  its 
perfectly  flexible  leather-like  test.  I  had  to  summon 
up  some  resolution  before  taking  the  weird  little 
monster  in  my  hand,  and  congratulating  myself  on 
the  most  interesting  addition  to  my  favourite  family 
which  had  been  made  for  many  a  day. 

Calveria  hystrix — for  I  have  named  this  genus  and 
species  after  our  excellent  Commander  and  his  tidy 


Fig.  28.— Calveria  hystrix,  Wvville  Thomson.     Inner  surface  of  a  portion  of  the  test  showing 
the  structure  of  the  anibulacral  and  interanibulacral  areas. 

little  vessel,  in  grateful  commemoration  of  the  plea- 
sant times  we  had  together — is  circular  and  depressed, 
rather  more  than  120  mm.  in  diameter,  and  about 
25  mm.  high  (Eig.  28).  Both  interambulacral  and 
ambulacral  areas  are  wide.  The  peristome  and  the 
periproct  are  unusually  large ;  the  former  covered  with 
calcareous  scale-like  plates,  perforated  up  to  the  rim  of 
the  mouth  for  the  passage  of  ambulacral  tube-feet,  as 
in  CidaiHs;  the  latter  with  a  large  madreporic  tubercle 


1  58  THE  DEPniH  OF  THE  SEJ.  [chap.  iv. 

and  five  large  round  openings  in  the  ovarial  plates 
in  the  centre  of  which  open  the  wide  ducts  from  the 
ovaries.  The  jaw  pyramid,  'Aristotle's  lantern/  is 
large  and  strong,  and  formed  on  the  plan  of  the  Dia- 
dematidse,  and  the  teeth  are  large  and  simply  chan- 
nelled. The  point  of  structure,  however,  in  which 
Calveria  differs  from  all  previously  described  recent 
urchins  is  the  arrangement  of  the  ambulacral  and 
interambulacral  plates.  These,  instead  of  meeting 
edge  to  edge  and  abutting  against  one  another  so  as 
to  form  a  continuous  rigid  shell  as  in  most  other 
echinids,  overlap  one  another  ;  the  plates  of  the  inter- 
ambulacral arese  from  the  apical  pole  towards  the 
mouth,  those  of  the  ambulacral  areee  from  the  mouth 
towards  the  apical  disk  (Pig.  28).  In  Calveria,  the 
outer  portions  of  the  interambulacral  plates  leave 
spaces  between  them  wliich  are  filled  up  with  mem- 
brane, and  the  inner  ends  of  the  plates  form  large  wide 
expansions,  which  overlap  greatly.  The  ambulacral 
pairs  of  pores  are  singularly  arranged :  they  are  in 
arcs  of  three,  but  two  of  the  pairs  of  each  arc  penetrate 
small  special  accessory  plates,  while  the  third  pair 
penetrates  the  ambulacral  plate  near  the  end.  The 
outer  ends  of  the  interambulacral  plates  overlap  the 
outer  ends  of  the  ambulacral  plates,  so  that  the 
ambulacral  arese  are  essentially  within  the  interambu- 
lacral. The  interambulacral  plates  bear  each  close  to 
the  outer  end  where  they  overlap  the  ambulacral 
plates,  a  large  primary  tubercle ;  and  two  imperfect 
rows  of  primary  tubercles  bearing  long  spines  are 
ranged  in  the  middle  of  the  ambulacral  arese;  the 
remainder  of  the  surface  of  the  plates  is  thickly 
studded  with  secondary  tubercles  and  miliary  grains. 


CHAP.  IV.] 


THE  CRUISES  OF  THE  '  F0RCUEL\E: 


151) 


The  spines  are  very  delicate  and  hollow,  with  pro- 
jecting processes  arranged  in  an  imperfect  spiral;  and 
resemble  somewhat  the  small  spines  of  the  Diade- 
matidse.    The  colour  of  the  test  is  a  rich  crimson  with 
a  dash  of  purple,  and  it  is  very  permanent ;  the  only 
perfect  specimen  procured  which  is 
preserved    in    spirit  has   not   lost 
colour  greatly  to  the  present  time. 
In    the   summer  of    1870,    Mr. 
Gwyn   Jeffreys,    dredging    on  the 
coast  of  Portugal,  took  two  nearly 
perfect  specimens  and  several  frag- 
ments  of  another    species  of  the 
genus    Calveria ;    and  subsequent 
careful  examination  of  fragments 
and   debris   has    shown    that   this 
second  species,  C  fenestrata^  occurs 
likewise  in  the  deep  water  off  the 
coast  of  Scotland  and  Ireland.    The 
interambulacral     plates    are    nar- 
rower, and   leave  larger  membra- 
nous spaces  between  them,  and  the 
great  key-like  overlapping  expan- 
sions in  the  middle  line  are  much 
larger.     The  spines  have  the  same 
form  and  are  arranged  nearly  in 
the    same   way;    but   parallel    to 
the    outer    row    of    large    spines 
on    each    interambulacral     space 
of   four   or    five   or    more  pedicellarise,  of  quite   a 
peculiar  type.      The  head  of  the  pedicellaria  which 
is  supported  on  a  long  stalk,  consists  of  four  valves 
(Pig.  29),  the  wide  terminal  portion  of  each  forming 


Fia.  29. — Calveria  fenestrata, 
Wyville  Thomson.  One  of 
the  four-valved  pedicellarise. 


there    is    a    row 


160  THE  DEPTHS  OF  THE  SE/l.  [chap.  iv. 

a  beautiful  double  fenestrated  frame,  with  a  peculiar 
twist  in  it  reminding  one  of  a  Campy lodiscus,  and  a 
very  elegant  erenated  border.  These  disks  are  raised 
on  delicate  hollow  pedicels,  which  expand  beneath, 
at  their  point  of  attachment  to  the  common  stalk. 
A  large  mass  of  muscle  envelopes  the  lower  part  of 
the  group  of  pedicels,  and  doubtless  determines  the 
movement  of  the  valves  in  reference  to  one  another. 

It  is  difficult  to  see  what  relation  in  position  the 
valves  can  occupy  when  the  instrument,  whatever 
may  be  its  use,  is  closed. 

We  now  steamed  onwards  to  the  south-east  for 
about  ten  miles,  and  put  down  our  dredge,  fully 
equipped  with  *  hempen  tangles  '  and  every  accessory 
device  for  entrapping  the  denizens  of  the  deep,  exactly, 
as  our  Commander  assured  us,  over  the  spot  where  we 
had  dredged  the  Roltenice  early  in  the  cruise.  We 
got  there  in  the  evening,  and  adopted  a  plan  which 
we  had  tried  successfully  once  or  twice  before;  we 
allowed  the  dredge  to  remain  down  all  night,  moving 
along  with  the  drift  of  the  vessel,  and  hauled  it  up 
in  the  early  morning.  I  do  not  believe  human 
dredger  ever  got  such  a  haul.  The  special  inhabit- 
ants of  that  particular  region — vitreous  sponges  and 
echinoderms — had  taken  quite  kindly  to  the  tangles, 
warping  themselves  into  them  and  sticking  through 
them  and  over  them,  till  the  mass  w^as  such  that  we 
could  scarc3ly  get  it  on  board.  Dozens  of  great  Hol- 
tenice,  like 

"  Wrinkled  heads  and  aged, 
Wit'u  silver  beard  and  hair," 


n 


a  dozen  of  the  best  of  them   breaking  off  just  at 
that    critical    point    where    everything    doubles   its 


CHAP.  IV.]  THE  CRUISES  OF  THE  'PORCUPINE:  161 

weight  by  being  lifted  out  of  the  water,  and  sink- 
ing slowly  away  back  again  to  our  inexpressible 
anguish ;  glossy  whisps  of  Hyalonema  spicules ;  a 
bushel  of  the  pretty  little  mushroom-like  Tisiphonia ; 
a  fiery  constellation  of  the  scarlet  Astropecten  temiis- 
pinus ;  while  a  whole  tangle  was  ensanguined  by  the 
*  disjecta  membra  '  of  a  splendid  Brisinga. 

There  was  not  much  in  the  dredge-bag  that  was 

new.    Some  large  Munidce,  with  their  '  spheery  eyne  ; ' 

some  fine  specimens  of  Kophohelemnon  mulleri;    an 

example   of  the  Euryalid,  Asleronyx  loveni,  nearly 

the  only  Scandinavian  echinoderm  which  we  had  not 

previously   taken ;    and   an   injured    specimen   of    a 

flexible  urchin,  w  hich  we  supposed  to  be  of  the  same 

:  species  as  that  procured  the  day  before,  although  it 

I  diflPered  greatly  in  colour,  being  of  a  uniform  pale 

grey.     Upon  further  examination,  however,  it  proved 

.to  be  the  type  of  a  totally  different  generic  group  of 

the  same  family. 

Fhormosoyna  placenta  resembles  Calveria  in  having 

jthe  perisom   flexible,  the  plates  overlapping  in  the 

same  way  and  in  the  same  directions  ;  but  the  plates 

overlap  one  another  only  slightly,  and  they  leave  no 

'membranous   spaces   between,  so   that  they  form   a 

-ontinuous  shell.     The  great  peculiarity  of  this  form 

s  that  the  upper  surface  is  quite  different  from  the 

ower.     Above,  the  ambulacral  and  interambulacral 

irese  are   well  defined  and  in   ordinary   proportion, 

l  he  interambulacral  arese  being  just  twice  as  wide 

IS  the   ambulacral,   and   the   spines   are   much  like 

hose  of  Calveria,  and   are   arranged  nearly  in  the 

ame  manner.     At  the  periphery  the  shell  comes  to 

kind  of  ridge,  and  alters  entirely ;  from  the  edge 

M 


162  THE  DEPTHS  OF  THE  SEA.  [chap,  it 

to  the  mouth  the  distinction  between  ambulacral 
and  interambulaeral  areae  is  apparently  lost,  and 
the  sutures  between  the  plates  can  scarcely  be  made 
out ;  the  pore  areae  are  reduced  to  mere  lines  of 
double  pores,  and  tlie  whole  of  the  surface  of  the 
shell  is  studded  over  uniformly  with  the  very  large 
areolae  of  primary  tubercles,  bearin^^  spines  which 
are  small  and  delicate  and  apparently  quite  out  of 
proportion  to  the  mass  of  muscle  connected  with 
them  which  fills  the  areolae.  As  in  Calveria,  the 
tubercles  are  perforated. 

We  have  thus  become  acquainted  with  three 
members  of  a  family  of  urchins  which,  while  differ- 
ing in  a  most  marked  way  from  all  other  knownj 
living  groups,  bear  a  certain  relation  to  some  of  these,' 
and  easily  fall  into  their  place  in  urchin  classification. 
They  are  '  regular  echinids,'  and  have  the  normalj 
number  and  arrangement  of  the  principal  parts. 
They  resemble  the  Cidaridse  in  the  continuation  ot| 
the  lines  of  ambulacral  pores  over  the  scaly  membrane! 
of  the  peristome  to  the  mouth,  and  they  approach! 
the  Diadematidae  in  their  hollow  spines,  in  the  form 
of  their  small  pedicellariae,  and  in  the  general  structure! 
of  the  jaw  pyramid.  From  both  of  these  families  the^ 
differ  in  the  imbricated  arrangement  of  the  plates  an^ 
in  the  structure  of  the  pore  areae,  to  the  widest  extend 
compatible  with  belonging  to  the  same  sub- order. 

Many  years  ago  Mr.  Wickham  Elower  of  Part 
Hill,  Croydon,  procured  a  very  curious  fossil  fron 
the  upper  chalk  of  Higham  near  llochester.  It  con 
sisted  of  a  number  of  series  of  imbricated  platei 
radiating  from  a  centre,  and  while  certain  sets  of  thes( 
plates  were  perforated  with  the  characteristic  doubL 


CHAP.  IV.]  THE  CRUISES  OF  THE  'PORCUPINE:  163 

pores  of  the  urchins,  these  were  absent  in  alternate 
series.  Some  points  about  this  fossil,  particularly 
the  imbricated  arrangement  of  the  plates  over  portions 
indicating  a  circle  at  least  four  inches  in  diameter, 
caused  great  difficulty  in  referring  it  to  its  place. 
Edward  Eorbes  examined  it,  but  would  not  hazard 
an  opinion.  The  general  impression  was  that  it  must 
be  the  scaly  peristome  of  some  large  urchin,  possibly 
of  a  large  CypJiosoma,  a  genus  abundant  in  the  same 
bed.  Some  years  after  the  discovery  of  the  first 
specimen,  a  second  was  obtained  by  the  Rev.  Norman 
Glass,  from  Charlton  in  Kent.  This  specimen  ap- 
peared at  first  to  solve  the  difficulty,  for  it  contained 
in  the  centre  a  well-developed  '  lantern  of  Aristotle ; ' 
there  then  was  the  peristome  of  the  urchin,  of  which 
Mr.  riower's  specimen  was  the  periproct.  The  late 
Dr.  S.  P.  Woodward  examined  the  two  specimens 
carefully,  and  found  that  the  question  was  not  so 
easily  settled.  He  detected  the  curious  reversal  of 
the  imbrication  of  the  plates  in  the  ambulacral  and 
interambulacral  areas  which  I  have  described  in 
Calveria,  and  at  one  fpoint  he  traced  the  plates  over 
the  edge  of  the  specimen,  and  found  that  they  were 
repeated  inverted  on  the  other  side.  With  great 
patience  and  great  sagacity  he  worked  the  thing  out, 
and  came  to  the  conclusion  that  he  was  dealing 
with  the  representative  of  a  lost  family  of  regular 
echinids. 

Woodward  names  his  new  genus  EcJiinothuria,  and 
describes  the  chalk  species,  E.  floris,  almost  as  fully 
and  accurately  as  we  could  describe  it  now  with  a  full 
knowledge  of  its  relations  —  for  EcJiinothuria  is 
closely  related  to    Culver  la  and  Fhormosoma.     In  all 

^i  2 


lG-4  TUE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

essential  family  characters  they  agree.  The  plates 
imbricate  in  the  same  directions  and  on  the  same 
plan,  and  the  structure  of  the  ambulacral  arese, 
which  is  so  special  and  characteristic,  is  the  same. 
Echinothuria  differs  from  Calveria  in  the  wider  inter- 
ambulacral  and  ambulacral  plates,  in  the  smaller 
amount  of  overlapping,  and  in  the  absence  of  mem- 
branous intervals;  and  from  Fhormosoma  it  differs 
in  having  the  structure  and  ornament  of  the  apical 
and  oral  surfaces  of  the  test  the  same. 

As  the  genus  Echinothuria  was  the  first  described, 
I  have  felt  justified  in  naming  the  family  the  Echino- 
thuridse.  I  have  done  this  with  the  greater  pleasure, 
as  it  brings  into  prominence  a  term  suggested  by 
my  late  friend  Dr.  Woodward,  whose  early  death 
was  a  serious  loss  to  science.  In  Dr.  Woodward's 
memoir,  the  following  curious  paragraph  occurs  : — 

"After  this  apparently  conclusive  demonstration, 
it  appears  desirable  to  give  a  name  to  this  fossil  and 
to  attempt  a  short  description,  although  its  rank  and 
affinities  are  still  a  matter  of  conjecture.  At  present 
it  is  one  of  those  anomalous  organisms  which  Milne 
Edwards  compares  to  solitary  stars  belonging  to  no 
constellation  in  particular.  The  disciples  of  Von  Baer 
may  regard  it  as  a  '  generalized  form '  of  echinoderm, 
coming,  however,  rather  late  in  the  geological  day. 
The  publication  of  it  should  be  acceptable  to  those 
who  base  their  hopes  on  the  '  imperfection  of  the 
geological  record,'  as  it  seems  to  indicate  the 
former  existence  of  a  family  or  tribe,  whose  full 
history  must  ever  remain  unknown.''  The  special 
bearings  of  the  discovery  of  this  group,  and  of 
several  other   animal   forms   allied   to   chalk  fossils 


I 


CHAP.  IV.]  THE  CRLflSES  OF  THE  'PORCUPINE:  165 

living  among  the  recent  chalk-mud  of  the  Atlantic 
sea-bed,  will  be  discussed  in  a  future  chapter. 

While  we  were  examining  our  wonderful  dredge- 
load  the  little  '  Porcupine '  was  steaming  slowly 
southwards — past  the  island  of  Rona,  and  Cape  Wrath 
looking  out  into  the  north  cold  and  blue,  with  the 
waves  now  curled  up  asleep  at  its  feet,  as  if  they 
never  did  any  harm ;  past  the  welcome  Butt  of  the 
Lews,  and  into  the  little  harbour  of  Stornoway.  Here 
we  remained  some  days;  not  sorry— even  although 
our  cruise  had  been  thoroughly  pleasant — to  exchange 
the  somewhat  cramped  routine  of  life  in  a  gun-boat 
for  the  genial  hospitalities  of  Stornoway  Castle. 

The  fauna  of  the  '  warm  area '  is  under  circum- 
stances altogether  special  and  peculiar,  which  must 
be  discussed  in  full  hereafter.  While  the  cold  area 
is  sharply  restricted,  the  warm  area  extends  con- 
tinuously from  the  Pseroes  to  the  Strait  of  Gibraltar. 
At  all  events  the  same  conditions  are  continuous ; 
but  as  will  be  explained  more  fully  hereafter,  the 
whole  600  or  700  fathoms  of  water  down  to  the 
bottom  at  the  mouth  of  the  Pseroe  Channel,  corre- 
sponds with  the  surface  layer  only  to  a  like  depth  in 
the  Eockall  Channel  or  in  the  Atlantic  basin.  The 
first  700  to  800  fathoms  in  all  cases  are  actually 
warm,  but  where  the  depth  greatly  exceeds  800 
fathoms,  there  is  a  mass  of  cold  water  beneath  sink- 
ing slowly  to  nearly  the  freezing-point.  The  bottom 
therefore,  the  habitation  of  the  fauna,  is  only  warm 
where  the  depth  is  not  greater  than  800  fathoms, 
and  in  such  a  case  only  can  the  term  'warm  area' 
be  correctly  applied.  Such  are  the  conditions  off 
Faeroe,  and   it   is    this   which    makes    the   contrast 


166  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

between  the  warm  and  cold  areas  so  marked  in  that 
region.  The  warm  area,  however,  even  as  thus 
restricted,  is  continuous  southwards  so  far  as  we 
know  indefinitely  for  the  North  Atlantic,  occupying 
the  zone  of  depth  along  the  coast  from  say  300  to  800 
fathoms.  At  great  depths  everywhere  the  climatal 
conditions  approach  those  of  the  cold  area,  and  the 
actual  character  of  a  fauna — an  assemblage  of  animals 
at  any  one  spot — must  depend  not  merely  upon  tem- 
perature but  upon  the  laws  regulating  the  distribu- 
tion of  deep-sea  animals  ;  a  subject  on  which  we  know 
as  yet  very  little. 

The  bottom  in  the  cold  area  in  the  Eaeroe  Channel 
is  rough  gravel.  That  in  the  warm  is  everywhere 
nearly  homogeneous  'globigerina  ooze.'  This  cir- 
cumstance alone  is  sufficient  to  determine  a  marked 
difference  in  the  habits  of  the  animals  and  their 
mode  of  life. 

B^eferring  then  to  the  foraminifera,  the  dredge  came 
up  throughout  the  warm  area  full  of  Glohigerlna  and 
Orbulina,  and  fine  calcareous  mud,  the  product  of  their 
disintegration.  Among  these  were  multitudes  of 
other  forms,  most  of  them  of  large  size.  I  quote  from 
Dr.  Carpenter.  Speaking  of  the  Holtenia  ground,  he 
says  : — ''  The  Foraminifera  obtained  on  this  and  the 
neighbouring  parts  of  the  warm  area  presented  many 
features  of  great  interest.  As  already  stated,  several 
arenaceous  forms  (some  of  them  new)  were  extremely 
abundant ;  but  in  addition  to  these  we  found  a  great 
abundance  of  Miliolines  of  various  types,  many  of 
them  attaining  a  very  unusual  and  some  even 
an  unprecedented  size.  As  last  year,  we  found 
Cornus'pirce  resembling  in  general  aspect  the  large 


CHAP.  IV.]  THE  CRUISES  OF  THE  'PORCUPINE:  167 

OperculincB  of  tropical  seas,  and  Biloculince  aud 
Triloculince  far  exceeding  in  dimensions  the  littoral 
forms  of  British  shores;  and  with  these  were  asso- 
cated  Cristellariw  of  no  less  remarkable  size,  pre- 
senting every  gradation  from  an  almost  rectilineal 
to  the  nautiloid  form,  and  having  the  animal  body  in 
so  perfect  a  state  as  to  enable  it  to  be  completely 
isolated  by  the  solution  of  the  shell  in  dilute  acid." 
Sponges  were  extremely  abundant,  but  they  were 
restricted  to  only  a  small  number  of  species ;  all  of 
them  with  one  form  or  another  of  the  curious  an- 
choring habit.  Among  the  Hexactinellidse  Holtenia 
was  the  most  striking  and  the  most  abundant  form. 
Hyalonema  was  also  common ;  but  we  got  few  per- 
fect specimens  with  the  sponge  and  glass-rope  in 
connection.  The  conical  sponge  heads  were  very 
numerous  ;  they  seemed  to  have  been  torn  off  by 
the  edge  of  the  dredge,  the  rope  remaining  in 
the  mud,  and  the  ropes  were  frequently  brought 
up  without  the  sponge.  Almost  all  the  ropes  were 
encrusted  with  the  constant  '  commensal '  of  Ilya- 
lonemay  JPalythoa  fatua.  Very  young  examples  of 
Hyalonema,  with  the  whisp  from  5  mm.  to  20  mm. 
long,  had  usually  no  Falythoa  on  them ;  but  when 
they  had  attained  above  the  latter  dimensions  in 
almost  every  case  one  could  see  the  first  polyp  of 
the  Falythoa  making  its  appearance  as  a  small 
bud,  and  its  pink-encrusting  coenosarc  spreading 
round  it.  By  far  the  most  common  sponge  in  the 
chalk-mud  is  the  pretty  little  hemispherical  corti- 
cate form  Tisiphonia  agariciformis.  This  species, 
though  difPering  from  it  greatly  in  appearance  and 
habit,  seems  to  be  closely  allied  to  a  strong,  heavy 


I 


168  THE  DEPTHS  OF  THE  SEA.  [cii/p.  iv. 

encrusting  sponge  which  we  met  with  frequently 
sticking  to  stones  in  the  '  cold  area.'  The  form  of 
the  spicules  was  nearly  though  not  quite  the  same, 
and  their  arrangement  was  very  similar.  It  appeared 
as  if  the  two  forms  placed  in  intermediate  circum- 
stances might  have  approached  one  another  very 
closely. 

In  the  warm  area,  as  in  the  cold  at  these  great 
depths,  there  is  a  singular  absence  of  Hydrozoa.  A 
few  species  of  SertulaiHa  and  Flmnularia,  and  one  or 
two  allied  forms  occurred,  and  they  are  now  in  the 
skilful  hands  of  Dr.  Allman  for  determination ;  but 
their  small  number  and  insignificance  is  remarkable. 

Neither  are  the  true  corals  represented  by  numer- 
ous   species,    although    in    some   places   individuals 
are  enormously  abundant.    During  the  '  Porcupine  ' 
cruises  of  1869  twelve  species  of  Madreporaria  were 
procured  which  have  been  determined  by  Professor 
Martin    Duncan.      None    of  these   belong  to    'reef- 
building'  genera,  but  to  a  group  which  are  recognized 
as  deep-sea  corals,  a  group  which  appears  to  have  had 
numerous  representatives  during  all  the  later  geolo- 
gical periods.      In  a  band   somewhat   restricted  in 
depth,   extending   downwards  from   the   100-fatliom 
line,  we  met  in  some  places  with  very  large  numbers 
of  many  varieties  of  Caryophyllia  horealis,  Pleming 
(Fig.  4) ;  and  at  depths  of  300  to  600  fathoms  the 
handsome   branching   LophoJielia  prolifera,   Pallas 
(Pig    30),  forms  stony  copses   covering  the  bottom 
for  many  miles,  the  clefts  of  its  branches  aflPording 
fully   appreciated    shelter     to    multitudes    of    Area 
nodulosa,   Psolus    squamatus,    Ophiopholis    aculeata, 
and  other  indolent  '  commensals.' 


CHAP.  IV  J 


THE  CRUISES  OF  THE  'FORCUFINEJ 


169 


Five  species  of  Amphihelia  are  cited  by  Professor 
Martin  Duncan  from  the  '  Porcupine '  expedition  : — 
A.  profunda,  Pourtales  ;  A.  oculata,  L.  sp. ;  A.  mio- 
cenica,  Seguenza;  A.  atlantica,  n.  sp. ;  and  A.  ornata, 


Fro.  SO.—Lophoheliaprolifera,  Pallas  (sp.).     Three-fourths  the  natural  size.     (No.  26.) 


n.  sp.  ;  and  on  one  or  two  occasions,  chiefly  on 'the 
verge  of  the  cold  area,  the  hempen  tangles  involved 
some  elegant  fragments  of  the  stony  coral  Allopora 
oculina,  Eiirenberg  (Pig.  31). 


170 


THE  DEPTHS  OF  THE  SEA. 


[chap.  IV. 


Although  many  of  the  echinoderms  of  the  cold 
area  are  common  to  the  warm,  the  general  fades 
of  the  echinoderm  fauna  is  different,  and  there  are 
a  numher  of  additional  and  very  striking  forms. 

Cldarls  papillata,  Leske,  is  abundant  at  moderate 


Fio.  31. — Allopora  ocuKna,  Ehbenbebo. 


depths.  On  our  second  visit  to  the  HoUenia  groun 
we  dredged  one  small  specimen  of  the  handsome 
urchin  already  described,  Forocidaris  purpurata, 
A   fine   brilliantlv-coloured    urchin    of   the   Echinus 


i 


CHAP.  IV  ]  THE  CRUISES  OF  THE  '  PORCUPINE:  171 

flemingii  group,  but  distinguished  from  U.  Jiemmgii 
by  characters  which  I  must  regard  as  of  specific 
value,  JEchinus  microstoma^  Wyville  Thomson,  was 
common  and  of  large  size ;  and  along  with  it  many 
very  beautiful  brightly-coloured  examples  of  the 
smallest  form  of  E.  norvegicus. 

The  three  species  of  the  Echinothuridae,  Calveria 
hystrix,  (7.  fenestrata,  and  Phormosoma  'placenta  have 
as  yet  been  met  with  in  this  region  only,  and  they 
seem  to  have  a  wide  distribution,  stretching  at  about 
the  same  depth  and  temperature  from  the  Psferoe 
Islands  to  the  south  of  Spain.  I  hear  from  Pro- 
fessor Alexander  Agassiz  that  Count  Pourtales  has 
dredged  fragments  of  one  of  the  species  under  nearly 
similar  circumstances  in  the  Strait  of  Plorida. 
Cribrella  sanguinolenta  was  in  thousands,  of  all 
colours — scarlet,  bright  orange,  and  chocolate  brown. 
Several  examples  were  found  of  a  fine  Scy taster, 
probably  identical  with  the  Asterias  canariensis  of 
D'Orbigny,  and  if  so  having  a  southern  distribu- 
tion. The  curious  little  JPedicellaster  typicus  of 
Sars  was  not  unfrequent ;  a  form  which  looks  very 
much  like  the  young  of  something  else.  One  small 
specimen  of  Pteraster  militaris  came  up  from  the 
Holtenia  ground,  but  with  the  exception  of  Astro- 
pecten  tenuispinus,  which  seemed  to  be  more  abun- 
dant than  ever,  the  characteristic  arctic  echino- 
derms  were  absent.  We  took  no  examples  here  of 
Toxopneustes  drobachiensis,  Tripylus  fragilis,  Ar- 
chaster  andromeda,  Cte7iodiscus  crispatus,  Astropecten 
arctiGus,  Buryale  linJcii,  OpMoscolex  glacialis,  or 
Antedon  escrichtii.  It  is  very  likely  that  there  may 
be  colonies  in  the  '  warm  area '  of  some  or  of  all  of 


172 


THE  DEPTHS  OF  THE  SEA. 


[chap.  IV. 


these — for  the  region  in  which  they  are  common 
under  very  diiferent  climatal  conditions  is  within  a 
few  miles,  and  there  is  no  intervening  barrier — but 


Fi0.  Z2.—Ophiomusiwn  lymani,  Wtville  Thomson.    Dorsal  surface  ;  natural  size.    (No.  45. 

they  certainly  are  not  abundant.  AmpMura  ahys- 
sicola,  Sars,  was  in  great  numbers  sticking  to  the 
sponges,  and  OpMacantha  spinulosa  was  nearly  as 
common  as  in  the  cold  area. 


CHAP.  IV.]  THE  CRUISES  OF  THE  ' FORCUFINE:  1 73 

We  took  one  or  two  small  examples  of  a  very  fine 
ophiurid,  of  which  larger  specimens  had  been  pre- 
viously found  at  about  the  same  depth  and  tem- 
perature during  the  second  cruise  of  the  same 
season  oflP  the  coast  of  Ireland.  This  form  probably 
ought  to  be  referred  to  Lyman's  genus  Ophiomusium, 


Fig.  iZ.—OpMomv.sium  lymani,  Wyville  Thomson.   Oral  surface. 

though  the  characters  of  the  genus  must  be  some- 
what altered  to  admit  it.  OpMomusium  eburneum, 
Lyman,  of  which  several  specimens  were  taken  by 
Count  Pourtales  at  depths  of  from  270  to  335 
fathoms,  off  Sandy  Key,  is  distinguished  by  the 
great    solidity    and    complete    calcification    of    the 


1 74  THE  DEPTHS  OF  THE  SEA,  [chap.  iv. 

perisom.  The  plates  of  the  disk  are  soldered 
together,  so  as  to  form  a  close  mosaic  (fMuaelov),  \{ 
The  mouth-papillae  are  fused  into  two  lines,  their 
numher  being  only  indicated  by  grooves.  The 
lateral  arm-plates  are  united  together  above  and 
below,  the  upper  and  lower  arm-plates  are  reduced  i 
to  mere  rudiments,  and  there  are  no  tentacle  pores 
beyond  the  first  arm-joints. 


Fig.  Si.—Dorymhus  thomsoni,  Norman.    Ouce  and  a  half  the  natural  size  ;  everywhere  in . . 

deep  water.  , 

?■■ 

In  our  new  species,  which  I  name  provisionally 
Ophiomusium  lymani,  the  diameter  of  the  disk  is 
28  mm.,  and  the  length  of  each  arm  100  mm.  in 
large  specimens.  The  two  lateral  arm-plates,  fused 
together  above  and  below,  form  complete  rings,  their 
distal  edge  notched  on  each  side  for  the  insertion  of 
seven  arm  spines,  of  which  the  lowest  is  much  longer 
than  the  rest.  The  dorsal  arm-plates  are  small  and 
diamond-shaped,  let  in  between  the  lateral  arm- 
plates  at   the    distal   end    of    their    upper    line    of 


CHAP.  IV.]  THE  CRUISES  OF  THE  'FORCUFINE:  175 

junction.  The  ventral  arm-plates  are  entirely  absent. 
This  is  a  large  handsome  star- fish.  I  am  not  aware 
of  any  fossil  form  which  can  be  referred  to  the  same 
genus;  but  it  looks  like  a  thing  which  might  be 
expected  to  have  congeners  in  the  upper  chalk. 
Holothurids  were  not  frequent,  but  the  singular 
little  JEchinocucuniis  typica  of  Sars,  covered  with 
spiny  plates,  turned  up  in  every  sifting. 


Fig.  Zb.—Amathia  carpenteri,  Nokman.    Once  and  a  half  the  natural  size.    (No.  47.) 

Crustacea  are  numerous ;  but  we  have  here  entirely 
lost  the  gigantic  Arctic  amphipods  and  isopods  of 
the  '  cold  area.'  A  pretty  little  stalk-eyed  form 
Dorynchus  thomsoni,  Norman  (Fig.  34),  small  and 
delicate,  and  very  distinct  from  all  previously  de- 
scribed species  of  the  genus,  is  very  widely  diffused. 


1  76  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

This  crab,  from  its  long  spiny  legs  and  liglit  body, 
very  often  comes  up  entangled  on  the  part  of  the  rope 
which  had  been  passing  over  the  ground.  Another 
handsome  new  species,  Amathia  carpenteri,  Nor- 
man (Fig.  35),  was  common  in  the  sandy  chalk- 
mud  of  the  '  Holtenia  ground.'  The  genus  had 
previously  been  familiar  as  a  Mediterranean  form. 

I  quote  from  a  preliminary  notice  of  the  Crus- 
tacea by  the  lie  v.  A.  Merle  Norman :  '^  Ethusa 
granulata  (sp.  n.),  the  same  species  as  that  found 
off  Valentia,  but  exhibiting  a  most  extraordinary 
modification  of  structure.  The  examples  taken  at 
110 — 370  fathoms  in  the  more  southern  habitat 
have  the  carapace  furnished  in  front  wdth  a  spi- 
nose  rostrum  of  considerable  length.  The  animal 
is  apparently  blind,  but  has  two  remarkable  spiny 
eye-stalks,  with  a  smooth  rounded  termination 
where  the  eye  itself  is  ordinarily  situated.  In  the 
specimens  however  from  the  north,  which  live  in 
542  and  705  fathoms,  the  eye-stalks  are  no  longer 
moveable.  They  have  become  firmly  fixed  in  their 
sockets,  and  their  character  is  quite  changed.  They 
are  of  much  larger  size,  approach  nearer  to  each 
other  at  their  base,  and  instead  of  being  rounded  at 
their  apices  they  terminate  in  a  strong  rostrate 
point.  No  longer  used  as  eyes,  they  now  assume  the 
functions  of  a  rostrum ;  while  the  true  rostrum  so 
conspicuous  in  the  southern  specimens  has,  marvellous 
to  state,  become  absorbed.  Had  there  been  only  a 
single  example  of  this  form  procured,  we  should  at 
once  have  concluded  that  we  had  found  a  monstrosity, 
but  there  is  no  room  for  such  an  hypothesis  by  which 
to  escape  from  this  most  strange  instance  of  modifi-^ 


OHAP.  IV.]  THE  CRUISES  OF  THE  'PORCUPINE:  177 

cation  of  structure  under  altered  conditions  of  life, 
i  Three   specimens    were    procured   on    two    different 
occasions,  and  they  are  in  all  respects  similar." 

Mollusca  are  much  more  abundant  and  varied 
in  the  warm  area  than  in  the  cold.  Mr.  Gwyn 
JeflPreys  remarks,  however,  that  there  is  not  such 
a  decided  diflPerence  in  the  MoUuscan  fauna  of  the 
two  regions  as  might  have  been  expected  from  the 
difference  in  their  conditions ;  very  many  species 
being  common  to  both.  At  500  fathoms  the  sponges 
are  full  of  Fecten  vitreus,  Chem.,  and  Columbella 
halioeti,  Jeffreys  ;  and  throughout  the  area  species 
occur  of  many  Molluscan  genera,  including  Lima, 
j  Dacridkmi,  Nucula,  Leda,  Montacuta,  Aximis,  Astarte, 
\  Tellina,  Newra,  Dentalium,  Cadulus,  Siphonoden- 
talium,  Rissoa,  Aclis,  Odostomia,  Aporrhais,  Fleuro- 
toma,  Fusus,  and  Fuccinmn. 

Taken  as  a  whole  the  fauna  of  the  warm  area  off 
jthe  north  of  Scotland  seems  to  be  an  extension  of 
la  fauna  with  which  we  are  as  yet  very  imperfectly 
acquainted,    occupying    what    we    must    now    call 
moderate   depths,    say   from    300   to   800    fathoms, 
along  coasts  which  are  bathed  by  currents  of  equa- 
torial water.      The  fauna  of  this  zone  is  evidently 
3xtremely  rich ;  and  as  it  is  beyond  the   reach  of 
ordinary  dredging  from  an  open  boat,  and  yet  not 
it  a  sufficient  depth  to  present  any  very  great  diffi- 
bulty  from  a  yacht  of  average  size,  its  exploration 
lieems  to  present  just  the  combination  of  adventure 
jind    novelty   to   stimulate    amateurs;    so    we   may 
'lope  shortly  to  have  its  conditions  and  distribution 
leared  up.     A  most  successful  step  in  this  direction 
las  been  made  already  by  Mr.  Marshall  Hall,  who, 


.1 

1  78  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

with  his  yacht  'Noma,'  and  with  the  aid  of  Mr. 
Saville  Kent,  has  thrown  a  good  deal  of  additional 
light  upon  the  zoology  of  the  '  warm  area '  off  the 
coast  of  Portugal. 

We  left  Stornoway  on  the  13th  of  Septemher,  and 
in  the  afternoon  dredged  for  a  few  hours  in  Loch 
Torridon  without  much  result.  Late  in  the  evening, 
steaming  down  Raasay  Sound,  we  came  upon  the 
luminous  forest  of  Favonarla  to  which  I  have  already 
referred.  At  noon,  on  the  14th,  we  were  ahreast  of 
the  Island  of  Mull,  and  on  the  15th  we  were  once 
more  moored  in  the  Abercorn  Basin,  Belfast,  where 
we  took  leave  of  the  '  Porcupine '  and  our  highly- 
valued  friends  her  captain  and  officers ;  in  the  hope 
of  meeting  them  again  shortly,  and  thoroughly 
satisfied  with  the  success  of  our  summer's  work. 

On  the  24th  of  March,  1870,  a  letter  was  read  at 
the  council  meeting  of  the  Boyal  Society  from  Dr.  Car- 
penter, addressed  to  the  President,  suggesting  that  an  . 
exploration  of  the  deep  sea,  such  as  was  carried  out 
during  1868  and  1869  in  the  regions  to  the  north  and 
west  of  the  British  Islands,  should  now  he  extended 
to  the  soutli  of  Europe  and  the  Mediterranean,  and 
that  the  council  of  the  Boyal  Society  should  recom- 
mend such  an  undertaking  to  the  favourable  con- 
sideration of  the  Admiralty,  with  a  view  to  obtain 
the  assistance  of  Her  Majesty's  Government,  as  on 
the  previous  occasions.  The  official  correspondence, 
with  reference  to  the  expedition  of  the  summer  of 
1870,  is  given  in  Appendix  A  to  the  present  chapter. 

It  was  intended,  as  on  the  previous  occasion,  to 
divide  this  year's  expedition  into  cruises;  and  again 
Mr.  Gwyn  Jeffreys  undertook  the  scientific  direction 


CHAP.  IV.]  THE  CRUISES  OF  THE  'PORCUPINE:  1 79 

of  the  first  cruise,  at  a  time  when  both  Dr.  Carpenter 
and  I  were  occupied  with  our  official  work.    A  young 
Swedish  naturalist,  Mr.  Joshua  Lindahl  of  the  Uni- 
I  versity   of    Lund,    accompanied   him    as    zoological 
I  assistant,  and  Mr.  W.  L.  Carpenter  took  charge  of 
:  the  chemical  department.     It  was  arranged  that  Mr. 
Jeffreys'    cruise  should    extend   from   Falmouth    to 
Gibraltar.      Dr.  C^arpenter  and   I  were   to  have  rc- 
ilieved  him  at  Gibraltar,  meeting  the  vessel  there,  and 
[to  have  worked  together  as  we  did  the  year  before; 
but  I  was  unfortunately  laid  up  with  an  attack  of 
fever,  and  the  whole  charge  of  the  last  cruise  in  the 
Mediterranean  rested  with  Dr.  Carpenter.     Owing  to 
this  untoward  circumstance,  I  must  give  at  second- 
hand the  brief  account  of  the  first  part  of  the  work 
of  the  year  1870  which  is  necessary  to  complete  the 
;  sketch  of  what  has   been   done   towards   the   illus- 
Itration   of  the   condition   and  fauna   of  the   North 
Atlantic.     In  the  Mediterranean  Dr.  Carpenter  found 
ithe  conditions  of  temperature  and  of  the  distribu- 
tion  of  animal   life   entirely  exceptional,   as  might 
have  been  to  a  certain  extent  anticipated  from  the 
exceptional  circumstances   of  that   land-locked   sea. 
The  investigation  of  1870  can  only  be  said  to  have 
1)roken  ground  towards  the  solution  of  a  series  of 
very  special  and  peculiar  problems ;  and  I  am  not 
in  a  position  to  go  farther  at  present  than  to  indicate 
the  general  results  at  which  my  colleague  has  arrived. 
The  '  Porcupine '  left  Falmouth  on  the  4tli  of  July, 
but  was  detained  in  the  Channel  for  several  days  by 
fogs  and  contrary  winds.     On  the  7th  of  July,  they 
reached  the  slope  from  the  plateau  of  the  Channel  to 
the  deep  water  of  the  Atlantic,  and  took  a  first  haul 


1  80  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

ill  567  fathoms.  Mr.  Jeffreys  reports  the  contents  of 
the  dredge  as  small  but  very  interesting.  Among 
the  mollusca  he  notes  Terehratula  septata,  Limopsis 
borealls,  Hela  tenella,  Verticordia  ahyssicola,  Turho 
Jilosus,  and  Rmgiciila  ventricosa.  Turbo  Jilosus  and 
its^  variety  T.  glabratus  had  previously  been  known 
only  as  fossils  in  the  tertiaries  of  Calabria  and  Mes- 
sina. Terehratula  septata,  Limopsis  borealis,  and 
Hela  tenella  are  likewise  fossil  in  the  Pliocene  beds  of 
southern  Italy,  and  are  found  living  in  the  Scandi- 
navian seas.  Mr.  Norman  notes  among  the  crus- 
taceans new  species  of  Ampelisca  and  of  six  other 
genera ;  and  the  beautiful  scarlet  Echimis  microstoma 
was  the  most  conspicuous  echinoderm. 

The  wind,  as  the  vessel  passed  over  the  slope  of  the 
Channel,  was  rather  too  light  for  successful  dredging ; 
the  drift-way  was  scarcely  sufficient  to  carry  the 
dredge  along.  The  tangles  were  most  valuable, 
coming  in  as  highly  effective  aids,  particularly  in 
securing  all  things  provided  with  anything  in  the 
form  of  spines  or  other  asperities. 

On  the  8th  the  first  haul  was  nearly  a  failure.    Other 
hauls  later  in  the  day,  at  690  and  500  fathoms,  gave 
important  results.     Rhynchonella  sicula,  Segued  za; 
Tleuro7iectia,  sp.  n.  ;  and  Actceoii,  sp.  n.,  occurred: 
besides   the   usual   northern   species.      Mr.   Norman 
reports  as  to  No.  3  :   "A  most  important  dredging, 
the  results  among  the  Crustacea  being  more  valu 
able   than   all    the   rest  put   together — at   any   ratel^ 
of  the  first  cruise.     It  contains   almost   all   of  the 
choicest  of  the  new   species   in  last   year's  expedi- 
tion,  and  four    stalk-eyed   crustaceans   of  great  in 
terest,   three   of    which    are   new,    and    the   fourth, 


CHAP.  IV.]  THE  CRUISES  OF  THE  'PORCUPINE:  181 

Geryon  tridens,  is  a  fine  Norwegian  species.  With 
these  are  associated  two  forms  of  a  more  southern 
character,  Inachus  dorsettensis  and  Ehalia  cranchii, 
^v\ncll  I  should  not  have  expected  at  so  great  a 
depth."  The  echinoderms  were  a  very  northern 
group.  They  included  Cidaris  papillata,  Echinus  nor- 
vegicus  and  E.  microstoma,  the  young  of  Brissopsis 
lyrifera,  Astropecten  arcticus,  Ar chaster  andromeda, 
and  A.  parellii,  with  a  small  specimen  of  Ophio- 
miisiiim  lymani,  several  examples  of  Ophiacantha 
sjnnulosa,  and  as  usual  one  or  two  of  the  universally 
distributed  Echinocucmnis  typica.  Dr.  Mcintosh,  to 
whom  the  annelids  were  referred,  notices  as  a  species 
supposed  to  be  specially  northern,  Thelepus  coro- 
natus,  Eab.;  and  Iloltenia  carpenteri,  our  familiar 
anchoring  sponge,  of  all  sizes  and  ages  and  in  consider- 
able numbers,  was  entangled  in  the  hempen  '  swabs.' 
July  9th. — The  wind  still  too  light  for  effective 
work.  Dredged  in  717  and  358  fathoms,  the  assem- 
blage of  moUusca  having  the  usual  character  of  being 
to  a  great  extent  common  to  the  recent  fauna  of  the 
seas  of  Norway  and  to  the  pliocene  fauna  of  Sicily 
and  the  Mediterranean.  It  included  on  this  occasion 
Terebratelta  spitzhergensis,  an  arctic  and  Japanese 
form,  Pecten  vitreus,  and  P.  aratus,  Leda  pernula, 
Trochus  suturalis,  Odostomia  nitens,  and  Fleurotoma 
hispidutum.  Among  the  echinoderms  w^as  a  fine 
specimen  of  Brisinga  endecacnemos,  Absjornsen, 
very  markedly  different  from  B.  coronata,  which  was 
the  form  commonly  met  with  in  the  north.  The 
corals  were  represented  by  Amphihelia  oculata  and 
Besmophyllum  crista-galli.  Among  the  annelids  were 
]?ista  cristata,  O.  P.  MtJLLER,  and  Trophonia  glauca, 


X82  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

Malmgren,  both  of  them  Arctic  species.  The  10th 
was  Sunday,  and  the  vessel  lay-to,  and  on  the  11th 
they  dredged,  still  on  the  slope  of  the  channel  plateau, 
with  nearly  the  same  result  as  before,  the  fauna 
maintaining  the  same  character. 

Mr.  Gwyn  Jeffreys  was  now  anxious  to  get  a  haul 
or  two  in  the  very  deep  water  off  the  mouth  of  the 
Bay  of  Biscay,  which  we  had  explored  successfully 
in  1869.  They  therefore  steamed  southwards,  going 
a  considerable  distance  without  dredging,  as  they 
were  afraid  of  (coming  in  contact  with  the  cable 
between  Brest  and  North  America.  When  they  got 
to  their  ground  unfortunately  bad  weather  set  in, 
and  they  were  obliged  to  make  for  Yigo.  On  Thurs-  i 
day,  July  14th,  they  passed  Cape  Pinisterre,  and 
dredged  in  81  fathoms  about  9  miles  from  the 
Spanish  coast.  Along  with  a  number  of  familiar 
forms,  some  of  them  with  a  wide  northern  exten- 
sion, they  here  took  on  the  tangles  two  specimens, 
one  young  and  one  apparently  mature,  both  con- 
siderably injured,  of  the  singular  Echinidean  already 
mentioned,  Calveria  fenestrata.  This  is  evidently 
not  a  rare  form  nor  is  it  confined  to  very  deep  water ; 
it  is  rather  remarkable  that  it  should  have  escaped 
notice  so  long.  On  the  15th,  they  sounded  in  from 
100  to  200  fathoms,  about  40  miles  from  Vigo,  and 
on  the  16th  took  one  or  two  hauls  in  Vigo  Bay  at 
a  depth  of  20  fathoms.  This  locality  had  already 
been  well-nigh  exhausted  by  Mr.  McAndrew  in  1849^ 
and  only  a  few  additions  were  made  to  his  list. 

They  left  Vigo  on  the  18th.     I   quote  from  Mr; 
Gwyn  Jeffreys : — 

"  Wednesday,  July  20tJi. — Dredged   all  day  witi 


CHAP.  IV.]  THE  CRUISES  OF  THE  'PORCUPINE: 


183 


considerable  success  at  depths  from  380  to  994 
fathoms  (Stations  14-16) :  the  wind  and  sea  had  now 
gone  down;  and  we  took  with  the  scoop-net  a  few 
living  specimens  of  Clio  cuspidata.  The  dredgings  in 
380  and  469  fathoms  yielded  among  the  moUusca 
Leda  lucida  (Norwegian  and  a  Sicilian  fossil),  Axinus 
eumyarius  (also  Norwegian),  Necera  obesa  (Spitz- 
bergen  to  the  West  of  Ireland),  Odostomia,  n.  sp.,  O. 
minuta  (Mediterranean),  and  Cerithium,  n.  sp.  ;  and 
among  the  echinoderms  were  Brisinga  endecacnemos 
and  Asteronyx  loveni.  But  the  results  of  the  dredg- 
ing in  994  fathoms  were  so  extraordinary  as  to  excite 
our  utmost  astonishment.  It  being  late  in  the  even- 
ing, the  contents  of  the  dredge  could  not  be  sifted 
and  examined  until  daylight  the  next  morning.  We 
then  saw  a  marvellous  assemblage  of  shells,  mostly 
dead,  but  comprising  certain  species  which  we  had 
always  considered  as  exclusively  northern,  and  others 
which  Mr.  Jeifreys  recognized  as  Sicilian  tertiary  fos- 
sils, while  nearly  40  per  cent,  of  the  entire  number 
of  species  were  undescribed,  and  some  of  them  repre- 
sented new  genera.  The  following  is  an  analysis  of 
the  moUusca  perfect  and  fragmentary  taken  in  this 
one  haul : — 


1S4  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

The  northern  species  above  referred  to  are  34  in  num- 
ber, and  include  Dacridmm  mtreum,  Nucula  pumila, 
Leda  lucida,  L.frlgida,  Verticordia  ahyssicola,  Necera 
jugosa,N.ohesa,  Tectura  fulva^  Mssurisepta  papillosa, 
Torellia  vestita,Pleurotoma  turricula,  Admete  viridula, 
Cylichna  alba,  Cyliclma  ovata,  Jeffreys  n.  sp.,  Bulla 
conulus,  S.  Wood  not  Deshayes  (Coralline  Crag), 
and  Scaphander  Uhrarius.  Leda  lucida,  Necera  jugosa, 
Tectura  fulva,  Fissurisepta  pap>illosa,  To7^ellia  vestita, 
as  well  as  several  other  known  species  in  this  dredging, 
are  also  fossil  in  Sicily.  Nearly  all  these  shells,  as 
well  as  a  few  small  echinoderms,  corals,  and  other 
organisms,  had  evidently  been  transported  by  some 
current  to  the  spot  where  they  were  found  ;  and  they 
must  have  formed  a  thick  deposit  similar  to  those  of 
which  many  tertiary  fossiliferous  strata  are  composed. 
It  seemed  probable  also  that  the  deposit  was  partly 
caused  by  tidal  action,  because  a  fragment  of  Melam- 
piis  myosotis  (a  littoral  pulmonibranch)  was  mixed 
with  deep-water  and  oceanic  Pectinibranchiates  and 
Lamellibranchiates.  None  of  the  shells  were  Miocene 
or  of  an  older  period. 

''This  remarkable  collection,  of  which  not  much 
more  than  one-half  is  known  to  conchologists,  not- 
withstanding their  assiduous  labours,  teaches  us  how 
much  remains  to  be  done  before  we  can  assume  that 
the  record  of  Marine  Zoology  is  complete.  Let  us 
compare  the  vast  expanse  of  the  sea-bed  in  the  North 
Atlantic  with  that  small  fringe  of  the  coast  on  both 
sides  of  it  which  has  yet  been  partially  explored,  and 
consider  with  reference  to  the  dredging  last  men- 
tioned what  are  the  prospects  of  our  ever  becoming 
acquainted   with    all    the    inhabitants   of    the   deep 


(HAP.  lY.]  THE  CRUISES  OF  THE  'PORCUPINE:  185 

throughout  the  g-lobe  !  We  believe,  however,  that  a 
thorough  examination  of  the  newer  Tertiaries  would 
materially  assist  us  in  the  inquiry  ;  and  such  exami- 
nation is  feasible  and  comparatively  easy.  Much 
good  work  has  been  done  in  this  line ;  but  although 
the  researches  of  Brocchi,  Bivona,  Cantraine,  Phi- 
lippi,  Calcara,  Costa,  Aradas,  Brugnone,  Seguenza, 
and  other  able  palaeontologists  in  the  south  of  Italy 
have  extended  over  more  than  half  a  century,  and 
are  still  energetically  prosecuted,  many  species  of 
molluscous  shells  are  continually  being  discovered 
there,  and  have  never  been  published.  Besides  the 
MoUusca  in  this  dredging  from  994  fathoms,  Pro- 
fessor Duncan  informs  us  that  there  are  two  new 
genera  of  corals,  and  Flabellum  distinctum,  which  last 
he  regards  as  identical  with  one  from  North  Japan. 
It  coincides  with  the  discovery  on  the  Lasitanian 
coasts  of  two  Japanese  species  of  a  curious  genus  of 
Mollusca,  Vertico7'dia,  both  of  which  are  fossil  in 
Sicily  and  one  of  them  in  the  Coralline  Crag  of 
Suffolk." 

In  the  same  dredging  there  are  a  number  of  very 
singular  undescribed  sponges,  many  of  them  recalling 
some  of  the  most  marked  characters  of  one  of  the 
sections  of  Ventriculates.  These  will  be  referred  to 
in  a  future  chapter. 

On  Thursday,  the  21st  of  July,  dredging  was 
carried  on  all  day  at  depths  from  600  to  1095  fathoms, 
lat.  39°  42'  N.,  long.  9°  43'  W.,  with  a  bottom  tempera- 
ture at  1095  fathoms  of  4°  3  C.  and  at  740  fathoms 
of  9°-4  C.  The  dredging  was  most  successful ;  many 
of  the  new  and  peculiar  mollusca  of  the  last  dredging 
were  taken  here  alive,  with  several  additional  forms. 


186  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

Several  imdescribed  crustaceans  were  added ; — a  new 
species  of  the  genus  Ccenocyathus  among  the  corals, 
and  a  species  of  an  unKnown  genus  allied  to  JBathy- 
cyathus.  Brisinga  endecacnemos  and  some  new  ophi- 
urids  were  part  of  the  treasures,  but  the  greatest 
prize  was  a  splendid  Fentacrmus  about  a  foot  long,  of 
which  several  specimens  came  up  attached  to  the  tan- 
gles. This  northern  Sea-lily,  on  which  my  friend  Mr. 
Gwyn  Jeffreys  has  bestowed  the  name  Fentacrinus 
iDyville-thomsoni,  will  be  described  hereafter  with  some 
other  equally  interesting  members  of  the  same  group. 

Cape  Espichel  was  reached  on  the  25th.  The 
weather  was  now,  however,  so  rough  that  Captain 
Calver  was  obliged  to  take  shelter  in  Setubal  Bay. 
Professor  Barboza  de  Bocage  of  Lisbon  had  given 
Mr.  Gwyn  Jeffreys  a  letter  of  introduction  to  the 
coastguard  officer  at  Setubal,  who  knew  the  place 
where  the  deep-sea  shark  and  the  Hyalonema  are 
taken  by  the  fishermen,  but  the  state  of  the  weather 
prevented  his  taking  advantage  of  it. 

Off  Cape  Espichel  in  740  and  718  fathoms,  with  a 
temperature  of  10°-2  C,  the  mollusca  were  much  the 
same  as  those  from  Station  16,  but  included  Leda 
pusio,  Limopsis  pygmcea  (Sicilian  fossils),  and  Verti- 
cordia  acuticostata.  The  last-named  species  is  in- 
teresting in  a  geological  as  well  as  a  geographical 
point  of  view.  It  is  fossil  in  the  Coralline  Crag 
and  the  Sicilian  Pliocene  beds,  and  it  now  lives  in  the 
Japanese  archipelago.  Mr.  Jeffreys  suggests  a  mode 
of  accounting  for  the  community  of  so  many  species 
to  the  eastern  borders  of  the  Atlantic  basin  and  the 
Mediterranean,  in  which  several  Japanese  brachi- 
opods   and  crustaceans    are    found,  and   the  seas  of 


CHAP.  IV.]  THE  CRUISES  OF  THE  'PORCUPINE:  187 

Northern  Asia,  by  supposing   a   migration  through 


Pig.  ^G.—Chondrodadia  virgafa,  Wyvillk  Thomsox.    One-half  the  natural  size.  (No.  3.3,  PI.  V.) 


the  Arctic  Sea.      We   must    know,    however,  much 


188  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

more  than  we  yet  do  of  tlie  extension  both  in  time 
and  space  of  the  fauna  of  deep  water  before  we  can 
come  to  any  certain  conclusion  on  these  questions. 

Dredging  across  the  entrance  of  the  Strait  of  Gib- 
raltar in  477,  651,  and  554  fathoms.  Stations  31,  32, 
and  33,  with  a  bottom  temperature  of  10°-3,  10°*1, 
and  10°  0  respectively,  many  remarkable  forms  were 
dredged,  including  a  very  elegant  sponge,  apparently 
allied  to,  if  not  identical  with,  Oscar  Schmidt's, 
Caminus  vulcani,  and  some  beautiful  forms  of  the 
Corallio-spongiae,  which  will  be  noticed  in  a  future 
chapter.  Station  No.  31  yielded  a  sponge  form 
which  recalled  the  branching  heather-like  Cladorhiza 
of  the  cold  area  off  Ejferoe.  Chondrocladia  virgata 
(Pig.  36)  is  a  graceful  branching  organism  from 
twenty  to  forty  centimetres  in  height.  A  branching 
root  of  a  cartilaginous  consistence,  formed  of  densely 
packed  sheaves  of  needle-shaped  spicules  bound 
together  by  a  structureless  organic  cement,  attaches 
the  sponge  to  some  foreign  body,  and  supports  it 
in  an  upright  position;  and  the  same  structure  is 
continued  as  a  solid  axis  into  the  main  stem  and  the 
branches.  The  axis  is  made  up  of  a  set  of  very  definite 
strands  like  the  strands  of  a  rope,  arranged  spirally, 
so  as  to  present  at  first  sight  a  strong  resemblance  to 
the  whisp  of  Kyalonema  ;  but  the  strands  are  opaque, 
and  break  up  under  the  point  of  a  knife  ;  and  under 
the  microscope  they  are  found  to  consist  of  minute 
needle-like  spicules  closely  felted  together.  The  soft 
sponge  substance  spreads  over  the  surface  of  the  axis 
and  rises  into  long  curving  conical  processes,  towards 
the  end  of  which  there  is  a  dark  greenish  oval  mass 
of  granular  sponge  matter,   and  the  outline  of  the 


CHAP.  IV.]  THE  CRUISES  OF  THE  '  PORCUPINE:  189 

cone  is  continued  beyond  this  by  a  number  of 
groups  of  needle-shaped  spicules  which  surround  a 
narrow  oscular  opening.  All  parts  of  the  sponge 
are  loaded  with  triple-toothed  'bihamate'  spicules 
of  the  sarcode. 

On  the  5th  of  August  the  '  Porcupine '  steamed  into 
Tangier  Bay,  after  ineffectually  trying  to  dredge  in 
190  fathoms  off  Cape  Spartel.  In  Tangier  Bay  two 
casts  were  taken  at  a  depth  of  35  fathoms.  The 
fauna  was  chiefly  British,  with  a  few  more  southern 
forms. 

On  the  6th  of  August  Mr.  Jeffreys  went  to  Gib- 
raltar, and  there  yielded  up  the  reins  to  Dr.  Car- 
penter, going  on  to  Sicily  via  Malta,  for  the  purpose 
of  examining  the  newer  tertiary  formations  in  the 
south  of  Italy,  and  the  collections  of  fossil  shells  at 
Catania,  Messina,  Palermo,  and  Naples,  in  connec- 
tion with  the  results  of  his  cruise. 

On  Monday,  the  15th  of  August,  Captain  Calver, 
with  Dr.  Carpenter,  who  fortunately  retained  the 
services  of  Mr.  Lindahl  as  assistant,  in  charge  of  the 
science  department,  steamed  out  into  the  middle  of 
the  Strait  for  the  purpose  of  commencing  a  series 
of  observations  on  the  currents  of  the  Strait  of 
Gibraltar. 

These  experiments,  which  at  the  time  were  not 
considered  very  satisfactory,  were  repeated  and  ex- 
tended in  the  summer  of  1871  by  Captain  JN'ares, 
R.N.,  and  Dr.  Carpenter,  in  II.M.S.  'Shearwater.' 
Their  curious  results  have  been  given  in  great  detail 
by  Dr.  Carpenter  in  the  Proceedings  of  the  Royal 
Society  of  London,  and  by  Captain  Nares  in  a  special 
report  to  the  Admiralty.      As  it  is  my  purpose  to 


190  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

confine  myself  at  present  almost  exclusively  to  the 
description  of  the  phenomena  of  the  deep  water  in  the 
Atlantic  so  far  as  these  have  been  worked  out,  I 
will  not  here  repeat  the  narrative  of  the  experiments 
in  the  Strait.  I  will,  however,  give  a  brief  sketch  of 
Dr.  Carpenter's  cruise  in  the  Mediterranean,  as  the 
remarkable  phenomena  connected  with  the  distribu- 
tion of  temperature  and  of  animal  life  which  he 
observed,  illustrate  while  they  contrast  with  the 
singularly  different  conditions  which  have  been 
already  described  in  the  outer  ocean. 

The  first  sounding  in  the  basin  of  the  Mediter- 
ranean was  taken  on  the  16th  of  August,  lat.  36°  0' 
N.,  long.  4°  40'  W.,  at  a  depth  of  586  fathoms,  with  a 
bottom  of  dark  grey  mud.  The  surface  temperature 
was  23°-6  C,  and  the  bottom  temperature  12°-8  C, 
about  three  degrees  higher  than  at  the  same  depth 
in  the  ocean  outside.  A  serial  sounding  was  taken  to 
determine  the  rate  of  the  diminution  of  temperature, 
with  the  following  curious  result  : — 

Surface 23°- 60. 

10  fathoms 20-9 

20       „  18-0 

30       „  17-5 

40       „  16-7 

50       „  15-6 

100       „  12-8 

586       „  12-8 


Thus  the  temperature  fell  rapidly  for  the  first  30 
fathoms,  more  slowly  for  the  next  20,  from  50  to  100 
lost  only  3°  C,  and  before  reaching  the  depth  of  a 
hundred  fathoms  had  attained  its  minimum  tempera- 


CHAP.  IV.] 


THE  CRUISES  OF  THE  'PORCUPINE: 


191 


ture,  there  being  no  further  diminution  to  the  bottom. 
This  serial  sounding  and  all  the  subsequent  tempera- 
ture observations  taken  during  the  Mediterranean 
cruise  showed  that  the  trough  of  the  Mediterranean 
from  the  depth  of  100  fathoms  downwards  is  filled 
with  a  mass  of  water  at  almost  exactly  the  same 
temperature  throughout,  a  temperature  a  little  above 
or  below  12°-75  C. 

The  following  instances  have  been  cited  by  Dr. 
Carpenter  from  the  earlier  observations  in  the  Medi- 
terranean basin,  to  show  the  great  uniformity  of  the 
bottom  temperature  for  all  depths  : — 


Number 

of 
Station. 

Depth 

in 

Fathoms. 

Bottom 
Tempera- 
ture. 

Surface 
Tempera- 
ture. 

41 

730 

13°-  4C. 

23"  •  6C. 

42 

790 

13  •  2 

23-2     1 

43 

162 

]3  -4 

23-8     1 

44 

455 

13  -0 

21  -0 

45 

207 

12  -4 

22  -6 

46 

493 

13  -0 

23  -0 

47 

845 

12  -6 

21  -0 

Position. 


.35^ 

57' K 

35 

45 

35 

24 

35 

42 

20" 

35 

36 

10" 

35 

29 

37 

25 

30" 

Long.  4' 


12'W. 
3  57 
3     i ' 30" 
3  00  30" 

2  29  30" 

1  56 

1  10  30" 


At  this  last  Station  (No.  47)  a  serial  sounding  was 
taken,  which  entirely  confirmed  the  results  of  the 
first  (No.  40)  :— 


Surface 20"  •  9  C. 


10  fathoms 15 


20 
30 
40 
50 

100 

845 


14 
13 
13 
13 
12 
12  -6 


192  THE  DEPTHS  OF  THE  SEJ.  [chap,  iv, 

— again  a  mass  of  water  lying  at  the  bottom,  745 
fathoms — not  far  from  a  mile — in  depth,  at  the 
uniform  temperature  of  12°*6  C.  (54!°-7F.) 

The  dredge  was  sent  down  at  each  successive 
station,  but  with  very  poor  result ;  and  Dr.  Car- 
penter was  driven  to  the  conclusion  that  the  bottom 
of  the  Mediterranean  at  depths  beyond  a  few  hundred 
fathoms  is  nearly  azoic.  The  conditions  are  not 
actually  inconsistent  with  the  existence  of  animal 
life,  for  at  most  of  the  stations  some  few  living  forms 
were  met  with,  but  they  are  certainly  singularly  un- 
favourable. Tlius  at  Station  49,  at  a  depth  of  1412 
fathoms,  and  a  temperature  of  12°* 7  C,  the  following 
species  of  mollusca  were  obtained  :  Nueula  quadrata, 
n.  sp. ;  N.  pumila,  Absjornsen  ;  Leda,  n.  sp. ;  Verti- 
cordia  grmitilata,  Seg.  ;  Ilela  tenella,  Jeffreys  ; 
Trochus  gemmulatus.  Ph.;  Bissoa  suhsoluta,  Aradas  ; 
Natica  affinis,  Gmelin  ;  Trophon  mtdtilamellosus, 
Ph.  ;  Nassa  prismatica,  Br.  ;  Columhella  halicBti, 
Jeff.  ;  Buccinium  acuticostatum,  Ph.  ;  Fleurotoma 
carmatum,  Cristofori  and  Jan  ;  P.  torqiiatum,  Ph.  ; 
P.  decussatum,  Ph. 

Near  the  African  coast  the  fauna  was  more  abun- 
dant, but  the  bottom  was  so  rough  that  it  was  unsafe 
to  use  the  dredge,  and  the  tangles  were  usually  sent 
down  alone.  Many  polyzoa,  echinoderms,  corals,  and 
sponges  were  taken  in  this  way,  but  they  were  mostly 
well-knewn  Mediterranean  species.  After  remaining 
for  a  few  days  at  Tunis  and  visiting  the  ruins  of 
Carthage,  dredging  was  resumed  on  the  6th  of 
September  on  the  '  Adventure'  Bank ,  so  called  from 
its  having  been  discovered  by  Admiral  Smyth  when 
surveying  in  H.M.S.  'Adventure.'     Here,  at  depths 


CHAP.  IV.]  THE  CRUISES  OF  THE  'PORCUPINE:  193 

from  30  to  250  fathoms,  animal  life  was  tolerably 
abundant.  With  other  mollusca  the  following  were 
found: — Trochus  siituralis,  Ph.  (Sicilian  fossil); 
Xeno'pliora  crispa,  Konig  (Sic.  fossil)  ;  Cylichna 
striatula,  Eohbes  (Sic.  fossil) ;  C.  ovulata,  Brocchi 
(Sic.  fossil) ;  Gadinia  excentrica,  Tiberi  ;  Scalcma 
frondosa,  J.  Sowerby  (Sicilian  and  Coralline  Crag 
fossil) ;  'Pyramidella  plicosa,  Bronn  (Sic.  and  Cor. 
Crag  fossil) ;  Actceon  pusillus,  Eorbes  (Sic.  fossil). 
The  Echinodermata  were  abundant  so  far  as  indi- 
viduals went,  but  the  number  of  species  was  small, 
and  they  were  nearly  all  well-known  Mediter- 
ranean forms.  Cidaris  papillata,  Leske,  showing 
many  varieties,  but  diflPering  in  no  specific  character 
from  the  many  forms  of  the  same  species  which 
range  from  North  Cape  to  Cape  Spartel  in  the 
ocean  outside.  The  Mediterranean  varieties  of  this 
species  are  certainly  Cidaris  hystrix,  of  Lamarck. 
I  feel  a  degree  of  uncertainty  about  the  pretty 
little  Cidm^is,  described  by  Philippi  under  the  name 
of  C.  affinis.  Characteristic  examples  of  it,  which 
are  abundant  on  the  'Adventure'  Bank  and  along 
the  African  coast,  look  very  distinct.  They  are  of 
a  beautiful  deep  rose  red,  the  spines  are  banded 
with  red  and  brownish-yellow,  and  come  to  a  fine 
point,  while  those  of  C.  papillata  are  usually  blunt 
at  the  point,  and  frequently  even  a  little  expanded 
or  cupped ;  and  the  portion  of  the  interambu- 
lacral  plates  covered  with  miliary  granules  is  wider, 
and  two  defined  rows  of  body  spines  nearly  of  equal 
size  lie  up  against  the  bases  of  the  primary  spines, 
over  the  alveolae.  These  would  appear  to  be  cha- 
racters of  specific  value,   but  then  again  there  are 

o 


194  THE  DEPTHS  OF  THE  SEA.  [chap. 

a  mass  of  intermediate  forms;  and  although  after^ 
careful  consideration  I  have  described  the  two 
species  as  distinct,  I  find  it  a  matter  of  great  diffi- 
calty  to  draw  the  line  between  them.  Several 
specimens  of  a  handsome  Astrogonium  allied  to 
A.  granular  e  were  taken  on  the  'Adventure ' 
Bank.  Professor  Duncan  reports  some  interesting 
corals,  and  Professor  AUman  two  new  species  of 
Aglaophenia ;  and  Dr.  Carpenter  detected  once 
more  the  delicate  Orhitolites  tenuissimus,  and  the 
large  nautiloid  \Lituola,  with  which  he  was  familiar 
in  the  dredgings  in  the  Atlantic. 

After  a  short  stay  at  Malta,  on  September  20th  the 
'Porcupine'  steamed  out  of  Yaletta  Harbour,  and 
steered  in  a  north-easterly  direction,  towards  a  point 
seventy  miles  distant,  at  which  a  depth  of  1700 
fathoms  was  marked  on  the  chart.  This  was  reached 
early  the  next  morning,  and  the  line  ran  out  1743 
fathoms,  lat.  36°  31'  30"  N.,  long.  15°  46^30"  (No.  60), 
with  a  temperature  of  13°*4  C,  more  than  half  a 
degree  higher  than  the  temperature  of  the  deepest 
sounding  in  the  western  basin.  The  tube  of  the 
sounding  apparatus  brought  up  a  sample  of  yellow 
clay,  so  like  the  bottom  at  some  of  the  most  unpro- 
ductive spots  in  the  western  Mediterranean,  that 
it  was  not  considered  advisable  to  delay  the  time 
necessary  for  even  a  single  cast  of  the  dredge,  which 
at  that  depth  would  have  occupied  nearly  a  day. 
Having  thus  satisfied  themselves  as  far  as  they 
could  by  a  few  observations  that  the  physical  con- 
ditions of  the  eastern  basin  of  the  Mediterranean 
were  similar  to  those  of  the  western,  they  steered  for 
the  coast  of  Sicily.    Quietly  along  the  Sicilian  coast 


CHAP.  IV.]  THE  CRUISES  OF  THE  '  PORCUPINE:  1 95 

during  the  night,  in  early  morning  through  the 
narrowest  part  of  the  Strait  between  Messina  and 
lieggio,  past  Charyhdis  and  the  castled  rock  of  Scylla, 
and  so  out  of  the  'Earo'  into  the  open  sea  to  the 
north  of  Sicily,  studded  with  the  I^ipari  Islands. 
A  temperature  sounding  taken  near  Stromboli,  lat. 
38°  26'  30"  N.,  long.  15°  32'  E.,  gave  a  depth  of  730 
fathoms,  and  a  bottom  temperature  of  13°*1  C,  while 
the  temperature  of  the  surface  was  22°*5  C. 

Under  the  rugged  cone  of  Stromboli  the  dredgers 
took  another  set  of  temperatures,  with  the  result  com- 
mon to  the  whole  volcanic  neighbourhood  of  Sicily, 
of  a  temperature  slightly  higher  than  that  of  the  deep 
water  in  the  western  basin  of  the  Mediterranean,  a 
phenomenon  of  which  it  would  take  long  and  careful 
observation  to  determine  the  cause  ;  and  while  doing 
so  they  pondered  on  the  cloud  of  smoke  hanging  over 
the  peak,  so  suggestive  of  the  theatre  of  subterranean 
change  beneath,  and  admired  the  industry  and  enter- 
prise of  those  who,  rendered  contemptuous  by  the 
familiarity  of  ages,  carried  their  vineyards  "  all  over 
the  cone,  save  on  two  sides,  looking  north-west  and 
south-east,  over  one  or  other  of  which  there  is  a  con- 
tinual discharge  of  dust  and  ashes." 

Their  course  w^as  now  laid  straight  for  Cape  de 
Gat,  which  they  passed  on  the  27th  of  September, 
arriving  at  Gibraltar  on  the  28th.  At  Gibraltar, 
Dr.  Carpenter  resumed  his  observations  and  experi- 
ments on  the  currents  of  the  Strait.  These  obser- 
vations were  continued  until  the  2nd  of  October, 
when  it  became  necessary  for  Captain  Calver  to  re- 
turn homewards.  The  coast  of  Portugal  was  repassed 
in  fine  weather,  the  time  at  their  disposal  not  allow- 


196 


THE  DEPTHS  OF  THE  SEA. 


[chap.  11 


iDg  any  further  use  of  the  dredge  in  the  deep  water, 
and  after  encountering  a  fresh  breeze  in  the  chops  of 
the  Channel,  on  the  evening  of  October  the  8th,  the 
'  Porcupine '  anchored  at  Cowes. 


CHAP.  IV.]  TIIU:  CRUISES  OF  THE  ' PORCUPINE:  197 


APPENDIX  A. 

Extracts  from  the  Minutes  of  Council  of  the  Royal  Society,  and 
other  Official  Documents  referring  to  the  Cruise  of  H.M.S. 
'  Porcupine  '  during  the  Summer  of  1870  : — 

March  24,  1870. 

A  Letter  was  read  from  Dr.  Carpenter,  addressed  to  the 
President,  suggesting  that  an  Exploration  of  the  Deep  Sea,  such 
as  was  carried  out  during  1868  and  1869  in  the  regions  to  the 
North  of  the  British  Islands,  should  now  be  extended  to  the 
South  of  Europe  and  the  Mediterranean,  and  that  the  Council 
of  the  Koyal  Society  should  recommend  such  an  undertaking  to 
the  favourable  consideration  of  the  Admiralty,  with  a  view  to 
obtain  the  assistance  of  Her  Majesty's  Government  as  on  the 
previous  occasions. 

Eesolved, — That  a  Committee,  consisting  of  the  President 
and  Officers,  with  the  Hydrographer,  Mr.  Gwyn  Jeffreys, 
Mr.  Siemens,  Professor  Tyndall,  and  Dr.  Carpenter,  with 
power  to  add  to  their  number,  be  appointed,  to  consider 
the  expediency  of  adopting  the  proposal  of  Dr.  Carpenter, 
and  the  plan  to  be  followed  in  carrying  it  out,  as  well 
as  the  instruments  and  other  appliances  that  would  be 
required,  and  to  report  their  opinion  thereon  to  the 
Council ;  but  with  power  previously  to  communicate  to  tlie 

(Admiralty  a  draft  of  such  report  as  they  may  agree  upon, 
if  it  shall  appear  to  them  expedient  to  do  so  in  order  to 
save  time. 
April  28,  1870. 
Eead  the  following  Report : — 

"  The  Committee  appointed  on  the  24th  of  March  to  consider 
a  proposal  for  a  further  Exploration  of  the  Deep  Sea  during  the 


198  THE  DEPTHS  OF  THE  SEA.  [chap.  iv. 

ensuing  summer,  as  well  as  the  scientitic  preparations  which 
would  be  required  for  a  new  expedition,  beg  leave  to  report  as 
follows : — 

"The  general  course  proposed  to  be  followed,  and  the  chief 
objects  expected  to  be  attained  in  a  new  expedition,  are  pointed 
out  in  the  following  extract  from  the  letter  of  Dr.  Carpenter, 
read  to  the  Council  on  the  24th  ult.,  which  was  referred  to  the 
Committee : — 

"  '  The  plan  which  has  been  marked  out  between  my  colleagues 
in  last  year's  work  and  myself  is  as  follows  : — 

" '  Having  reason  to  hope  that  the  "  Porcupine  "  may  be  spared 
towards  the  end  of  June,  we  propose  that  she  should  start  early 
in  July,  and  proceed  in  a  S.W.  direction  towards  the  furthest 
point  to  which  our  survey  was  carried  last  year;  carefully 
exploring  the  bottom  in  depths  of  400  to  800  fathoms,  on 
which,  as  experience  has  shown  us,  the  most  interesting  collec- 
tions are  to  be  made ;  but  also  obtaining  a  few  casts  of  the 
Dredge  with  Temperature-soundings  at  greater  depths,  as  oppor- 
tunities may  occur. 

" '  The  course  should  then  be  nearly  due  South,  in  a  direction 
of  general  parallelism  with  the  coast  of  France,  Spain,  and 
Portugal,  keeping  generally  within  the  depths  just  mentioned, 
but  occasionally  stretching  westwards  into  yet  deeper  waters. 
Prom  what  has  been  already  done  in  about  400  fathoms'  water 
off  the  coast  of  Portugal,  there  is  no  doubt  that  the  ground  is 
there  exceedingly  rich.  When  approaching  the  Straits  of 
Gibraltar,  the  survey,  both  Physical  and  Zoological,  should  be 
carried  out  with  great  care  and  minuteness ;  in  order  that  the 
important  problem  as  to  the  currents  between  the  Mediterranean 
and  Atlantic  Seas,  and  the  relation  of  the  Mediterranean  Fauna 
to  that  of  the  Atlantic  (on  which  Mr.  Gwyn  Jeffreys  is  of 
opinion  that  the  results  of  our  last  year's  work  throw  an  entirely 
new  light),  may  be  cleared  up. 

" '  Mr.  Gwyn  Jeffreys  is  prepared  to  undertake  the  scientific 
charge  of  this  part  of  the  expedition ;  and  if  Professor  Wyville 
Thomson  should  not  be  able  to  accompany  him,  it  will  not  be 
difficult  to  find  him  a  suitable  assistant. 

"  '  The  ship  would  probably  reach  Gibraltar  early  in  August, 


aiAP.  iv.J  TEE  CRUISES  OF  THE  ' porcupine:  199 

and  there  I  sliould  be  myself  prepared  to  join  her,  in  place  of 
Mr.  Jeffreys,  with  one  of  my  sons  as  an  assistant.  We  should 
propose  first  to  complete  the  survey  of  the  Straits  of  Gibraltar, 
if  that  should  not  have  been  fully  accomplished  previously ;  and 
then  to  proceed  eastwards  along  the  Mediterranean,  making 
stretches  between  the  coasts  of  Europe  and  Africa,  so  as  to  carry 
out  as  complete  a  survey,  Physical  and  Zoological,  of  that  part 
of  the  Mediterranean  basin  as  time  may  permit.  Malta  would 
probably  be  our  extreme  point ;  and  this  we  should  reckon  to 
reach  about  the  middle  of  September. 

" '  It  is  well  known  that  there  are  questions  of  great  Geolo- 
gical interest  connected  with  the  present  distribution  of  Animal 
life  in  this  area ;  and  we  have  great  reason  to  believe  that  we 
shall  here  find  at  considerable  depths  a  large  number  of  Tertiary 
species  which  have  been  supposed  to  be  extinct.  And  in  regard 
to  the  Physics  of  the  Mediterranean,  it  appears,  from  all  that 
we  have  been  able  to  learn,  that  very  little  is  certainly  known. 
The  Temperature  and  Density  of  the  water,  at  different  depths, 
in  a  basin  so  remarkably  cut  off  from  the  great  ocean,  and 
having  a  continual  influx  from  it,  form  a  most  interesting  sub- 
ject of  inquiry,  to  which  we  shall  be  glad  to  give  our  best 
attention,  if  the  means  are  placed  within  our  reach.' 

"  Considering  the  success  of  the  two  previous  Expeditions,  and 
especially  that  of  the  *  Porcupine '  last  year,  the  Committee  are 
persuaded  that  no  less  important  acquisitions  for  the  furtherance 
of  scientific  knowledge  would  be  gained  by  the  renewed  explora- 
tion as  now  proposed ;  and  they  aocordingly  recommend  that  a 
representation  to  that  effect  be  made  to  the  Admiralty,  with  a 
view  to  obtain  the  aid  of  Her  Majesty's  Government  as  on  the 
previous  occasions. 

"  The  Committee  approve  of  a  proposal  made  by  Mr.  Gwyn 
Jeffreys  to  accept  the  services  of  Mr.  Lindahl,  of  Lund,  in  the 
expedition  as  unpaid  Assistant  !N"aturalist. 

"As  regards  scientific  instruments,  the  Committee  have  to 
report  that  those  employed  in  last  year's  voyage  will  be 
again  available  for  use ;  and  Mr.  Siemens  hopes  to  render 
his  electro-thermal  indicator  of  more  easy  employment  on 
ship-board. 


200  THE  DEPTHS  OF  THE  SEA  [chap,  iv] 

"  The  Committee,  having  learned  that  Dr.  Frankland  has  con-i 
trived  an  apparatus  for  bringing  up  the  deep-sea  water  chargec 
with  its  gaseous  contents,  have  resolved  to  add  his  name 
their  number ;  and  they  request  leave  to  meet  again  in  ordei 
to  complete  the  arrangements  and  make  a  final  report  to  the 
Council." 

Eesolved, — That  the  Eeport  now  read  be  received  and  adopted] 
and  that  the   Committee  be  requested  to  continue  their' 
meetings  and  report  again  on  the  arrangements  when  finally 
decided  on. 

Eesolved, — That  the  following  draft  of  a  Letter  to  be 
addressed  to  the  Secretary  of  the  Admiralty  be  approved, 
viz. : — 

"  Sir, — I  am  directed  by  the  President  and  Council  of  the 
Eoyal  Society  to  acquaint  you,  for  the  information  of  the 
Lords  Commissioners  of  the  Admiralty,  tliat,  considering  the 
important  scientific  results  of  the  Physical  and  Zoological 
Exploration  of  the  Deep  Sea  carried  on  in  1868  and  1869 
through  the  aid  of  Her  Majesty's  Government,  they  deem  it 
highly  desirable  that  the  investigation  should  be  renewed  during 
the  ensuing  summer,  and  extended  over  a  new  area. 

"  The  course  which  it  would  be  proposed  to  follow  in  a  new 
Expedition,  the  principal  objects  to  be  attained,  and  the  general 
plan  of  operations,  are  sketched  out  in  the  enclosed  extract  from 
a  Letter  addressed  to  the  President  by  Dr.  Carpenter,  and  have 
in  all  points  been  approved  by  the  Council. 

"  The  President  and  Council  would  therefore  earnestly  recom- 
mend such  an  undertaking  to  the  favourable  consideration 
of  My  Lords,  with  the  view  of  obtaining  the  assistance  of 
Her  Majesty's  Government  so  liberally  accorded  and  effectively 
rendered  on  the  previous  occasions. 

"The  scientific  conduct  of  the  expedition  would,  as  in  the 
last  year,  be  shared  by  Dr.  Carpenter,  Professor  Wy  ville  Thomson, 
provided  that  gentleman  is  able  to  undertake  the  duty,  and  Mr. 
Gwyn  Jeffreys.  It  is  also  proposed  that  Mr.  Lindahl,  a  young 
Swedish  gentleman  accustomed  to  marine  researches,  should 
accompany  the  expedition  as  Assistant  Naturalist. 


HAr.  IV.]       tht:  cruises  of  the  '  porcupine:  201 


"  I  have  to  add  that  whatever  appertains  to  the  strictly 
Scientific  equipment  of  the  Expedition  will,  as  formerly,  be  at 
the  charge  of  the  Eoyal  Society. 

**  W.  Sharpey,  Secretary." 

A  sum  of  £100  from  the  Government  Grant  was  assigned 
for  the  Scientific  purposes  of  the  Expedition. 

May  19,  1870. 
Eead  the  following  Letter  from  the  Admiralty  : — 

"Admiralty,  \Oth  May,  1870. 
"  Sir, — Having  laid  before  My  Lords  Commissioners  of  the 
Admiralty  your  letter  of  the  2nd  inst.,  requesting  that  further 
researches  may  be  made  of  the  deep  sea,  I  am  commanded  by 
their  Lordships  to  acquaint  you  that  they  will  spare  Her 
Majesty's  Steam- vessel  '  Porcupine '  for  this  service,  and  that  the 
Treasury  have  been  requested,  as  on  the  former  occasion,  to 
defray  the  expense  of  the  messing  of  the  scientific  gentlemen 
composing  the  Expedition. 

"  I  am.  Sir, 

"  Your  obedient  Servant, 

''  Vernon  Lushington.'* 

''To  W.  Sharpey,  Esq.,  M.D., 
**  Secretary  of  the  Royal  Society,  Burlington  House!'' 


202 


THE  DEPTHS  OF  THE  SEA. 


[chap.  IV 


APPENDIX  B. 


Particulars  of  DeptJis,  Temperature,  and  Position  at  the  various 
Dredging-stations  of  H.M.S.  ^  Porcupine^'  in  tlie  Summer 
of  1870 :— 


Number     Depth  in 
of  Station.  Fathoms. 


1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 


Bottom 
Temperature. 


567 
305 
690 
717 
100 
358 
93 
257 
539 
81 
332 
128 
220 
469 
722 
994 
1095 
1065 
248 
965 
620 
718 
802 
292 


14°'  8  C. 


7 

10 

10 

10 

9 

8 

11 

10 

11 

11 

10 

9 

4 

4 

4 

11 

10 

10 

9 

11 


Surface         j 
Temperature.    | 


Position. 


16°-  2  C. 

16-3 

16 

•8 

16 

9 

16 

•2 

15 

9 

17 

8 

16 

4 

16 

1 

16 

3 

18 

1 

18 

4 

20 

0 

21 

0 

19 

8 

18 

2 

18 

1 

19 

5 

19 

1 

19 

0 

19 

6 

48^ 

38' K 

48 

37 

48 

31 

48 

32 

48 

29 

48 

26 

48 

18 

48 

13 

48 

6 

42  44   1 

42 

32 

42 

20 

40 

16 

40 

6 

40 

2 

39 

55 

39  42   1 

39 

29 

39  27   1 

39 

25 

38 

19 

38 

15 

37  20   1 

37 

19 

10°  15'  W. 
10     9 
10     3 

9  59 

9  45 

9  44 

9  11 

9  11 

9  18 

9  23 

9  24 

9  17 


37 
44 
49 
56 
43 
44 


9  39 
9  45 


30 
33 
30 
13 


CHAP.  IV.]  THE  CRUISES  OF  THE  '  PORCUPINE: 


203 


1 

Number 

Depth  in 

Bottom 

Surface 

I'osit^"" 

of  Station. 

Fathoms. 

Temi)erature. 

Temperature. 

1 

25 

374 

ir-9C. 

20°-  9  C. 

37°  11'  N. 

9°    7'W. 

26 

364 

11  • 

5 

22 

0 

36  44 

8     8 

27 

322 

10 

6 

22 

7 

36  37 

7  33 

28 

304 

11 

7 

21 

8 

36  29 

7  16 

28a 

286 

— 

- 

36  27 

6  54 

29 

227 

12 

9 

22 

8 

36  20 

6  47 

30 

386 

11 

7 

22 

6 

36  15 

6  52 

31 

477 

10 

3 

21 

7 

35  56 

7    6 

32 

651 

10 

1 

21 

8 

35  41 

7    8 

33 

554 

10 

0 

22 

4 

35  32 

6  54 

34 

414 

10 

1 

21 

8 

35  44 

6  53 

35 

335 

10 

9 

23 

•2 

35  39 

6  38 

36 

128 

12 

9 

23 

8 

35  35 

6  26 

37 

190 

11 

8 

22 

•0 

35  50 

6     0 

38 

503 

11 

8 

22 

•0 

35  58 

5  26 

39 

517 

13 

3 

21 

•0 

35  59 

5  27 

40 

586 

13 

•4 

23 

•6 

36     0 

4  40 

41 

730 

13 

4 

23 

•6 

35  57 

4  12 

42 

790 

13 

2 

23 

•  2 

35  45 

3  57 

43 

162 

13 

•4 

23 

•8 

35  24 

3  54 

44 

455 

13 

•0 

21 

•0 

35  42 

3     0 

45 

207 

12 

•4 

22 

•6 

35  36 

2  29 

46 

493 

13 

•0 

23 

•0 

35  39 

1  56 

47 

845 

12 

•6 

21 

•0 

37  25 

1  10 

48 

1328 

12 

•  8 

23 

•0 

37  10 

0  31 

49 

1412 

12 

•7 

22  -0 

36  29 

0  31 

50 

51 



— 

36  14 

0  17  E. 

ma 

152 



— 

36  18 

0  24 

51 

1415 

12-7 

24-0 

36  55 

1  10 

52 

660 





36  38 

1  38 

52a 

-590 



— 

36  36 

1  38 

53 

112 

13-0 

25  •  0 

36  53 

5  55 

54 

1508 

13  -0 

24-4 

37  41 

6  27 

55 

1456 

12  -8 

24-  8 

37  29 

6  31 

56 

390 

13-6 

25  -6 

37     3 

11  37 

57 

224 



— 

37     6 

13  10 

58 

266 

13-6 

24-  1 

36  43 

13  36 

59 

445 

13-6 

24-6 

36  32 

14  12 

60 

1743 

13-4 

23-3 

36  31 

15  46 

204 


THE  DEPTHS  OF  THE  SEA. 


[chap.  IV. 


Number 

Depth  in 

Bottom 

Surface 

of  Station. 

Fathoms. 

Temperature. 

Temperature. 

61 

392 

13°-  1  C. 

22°-  5  C. 

38°  26'  K 

15°32'E. 

62 

730 

13  -0 

22-5 

38  38 

15  21 

63 

181 

12  -4 

20-2 

36     1 

5  26  W. 

64 

460 

12  -4 

18  -8 

35  58 

5  28 

65 

198 

12  •  1 

17-3 

35  50 

5  57 

66 

147 

— 

35  56 

5  57 

67 

188 

12  -8 

22  -9 

35  49 

6  21 

CHAPTER  V. 

DEEP-SEA     SOUNDING. 

The  ordinary  Sounding-lead  for  moderate  Depths.  —  Liable  to  Error 
when  employed  in  Deep  Water.  —  Early  Deep  Soundings  un- 
reliable.— Improved  Methods  of  Sounding. — The  Cup-lead. — 
Brooke's  Sounding  Instrument. — The  *  Bull-dog ' ;  Fitzgerald's  ; 
the  *  Hydra.' — Sounding  from  the  *  Porcupine.' — The  Contour 
of  the  Bed  of  the  North  Atlantic. 

In  all  deep-sea  investigations  it  is  of  course  of  the 
first  importance  to  have  a  means  of  determining  the 
depth  to  the  last  degree  of  accuracy,  and  this  is  not 
so  easy  a  matter  as  might  be  at  first  supposed. 
Depth  is  almost  invariably  ascertained  by  some 
modification  of  the  process  of  sounding.  A  weight 
is  attached  to  the  end  of  a  line  graduated  by  attached 
slips  of  different  coloured  buntine  (the  woollen  mate- 
rial of  which  flags  are  made,  in  which  the  colours  are 
particularly  bright  and  fast)  into  fathoms,  tens  of 
fathoms,  and  hundreds  of  fathoms ;  or,  for  deep-sea 
work,  with  white  buntine  at  every  50,  black  leather 
at  every  100,  and  red  buntine  at  every  1,000  fathoms. 
The  weight  is  run  down  as  rapidly  as  possible,  and 
the  number  of  fathoms  out  when  the  lead  touches 
the  bottom  gives  a  more  or  less  close  approximation 
to  the  depth. 


206  THE  DEPTHS  OF  THE  SEA.  [chap.  v. 

The  ordinary  deep-sea  lead  is  a  prismatic  leaden 
block  about  two  feet  in  length  and  80  to  120  lbs.  in 
weight,  narrowing  somewhat  towards  the  upper  end, 
where  it  is  furnished  with  a  stout  iron  ring.  Before 
heaving,  the  lead  is  '  armed,'  that  is  to  say  the  lower 
end,  which  is  slightly  cupped,  is  covered  with  a  thick 
coating  of  soft  tallow.  If  the  lead  reach  the  bottom 
it  brings  up  evidence  of  its  having  done  so  in  a 
sample  sticking  to  the  tallow.  Usually  there  is 
enough  to  indicate  roughly  the  nature  of  the  ground, 
and  it  is  on  the  evidence  of  samples  thus  brought 
up  on  the  *  arming '  of  the  lead  that  our  charts  note 
'mud,'  'shells,'  'gravel,'  'ooze,'  or  'sand,'  or  a  com- 
bination of  these,  as  the  kind  of  bottom  at  the 
particular  sounding  ;  thus  we  have  m^sTs.j  mud,  shells, 
and  sand  at  2,000  fathoms ;  o^z.^st.>  ooze  and  stones  at 
2,050  fathoms;  m. f'sh%c.j  niud,  sand,  shells,  and  scoriae 
at  2,200  fathoms,  and  so  on. 

When  no  bottom  is  found,  that  is  to  say,  when 
there  is  no  arrest  to  the  running  out  of  the  line 
and  nothing  on  the  'arming'  of  the  lead,  the  sounding 
is  entered  on  the  chart  thus,  3-^^,  no  bottom  at  3,200 
fathoms.  Such  soundings  are  not  to  be  depended 
upon  in  deep  water,  but  they  are  usually  quite 
reliable  for  moderate  depths,  so  far  as  they  go.  They 
give  us  no  help  in  the  exploration  of  the  bottom  of 
the  sea,  but  they  are  of  great  practical  value,  and 
indeed  they  give  all  the  information  which  is  directly 
required  for  the  purposes  of  navigation  ;  for  if  there 
be  'no  bottom'  at  200  fathoms,  there  is  probably  no 
dangerous  shoal  in  the  immediate  neighbourhood. 

Soundings  are  usually  taken  from  the  vessel,  and 
while  there  is  some  way  on.     Where  great  accuracy 


CHAP,  v.]  DEEP-SEA  SOUNDING.  207 

is  required,  as  in  coast-surveying,  it  is  necessary  to 
sound  from  a  boat,  which  can  be  kept  in  position  by 
the  oars  and  reference  to  some  fixed  objects  on  shore. 
This  ordinary  system  of  sounding  answers  perfectly 
well  for  comparatively  shallow  water,  but  it  breaks 
down  for  depths  much  over  1,000  fathoms.  The 
weight  is  not  sufficient  to  carry  the  line  rapidly  and 
vertically  to  the  bottom ;  and  if  a  heavier  weight  be 
used,  ordinary  sounding  line  is  unable  to  draw  up  its 
own  weight  along  with  that  of  the  lead  from  great 
depths,  and  gives  way.  No  impulse  is  felt  when  the 
lead  reaches  the  bottom,  and  the  line  goes  on  running 
out,  and  if  any  attempt  be  made  to  stop  it  it  breaks. 
In  some  cases  bights  of  the  line  seem  to  be  carried 
along  by  submarine  currents,  and  in  others  it  is 
found  that  the  line  has  been  running  out  by  its  own 
weight  only,  and  coiling  itself  in  a  tangled  mass 
directly  over  the  lead.  All  these  sources  of  error 
vitiate  very  deep  soundings.  In  many  of  the  older 
observations  made  by  officers  of  our  own  navy  and 
of  that  of  the  United  States,  the  depth  returned 
for  many  points  in  the  Atlantic  we  now  know  to 
have  been  greatly  exaggerated;  thus  Lieutenant 
Walsh,  of  the  U.S.  schooner  '  Taney,'  reported  a  cast 
with  the  deep-sea  lead  at  34,000  feet  without 
j  bottom;^  Lieutenant  Berryman,  of  the  U.S.  brig 
j  'Dolphin,'  attempted  unsuccessfully  to  sound  mid- 
ocean  with  a  line  39,000  feet  long ;  ^  Captain 
Denham,  of  H.M.S.  'Herald,'  reported  bottom  in  the 

^  Maury's  Sailing  Directions,  5tli  edition,  p.  165,  and  6th  edition 
j  (1854),  p.  213. 

I       2  Maury,    Physical   Geography   of    the    Sea.      Eleventh    edition, 
I  p.  309. 


208  THE  DEPTHS  OF  THE  SEA.  [chap.  v. 

South  Atlantic  at  a  depth  of  46,000  feet;'  and 
Lieutenant  Parker,  of  the  U.S.  frigate  '  Congress,'  ran 
out  a  line  50,000  feet  without  reaching  the  bottom.^ 
In  these  cases,  however,  the  chances  of  error  were 
too  numerous ;  and  in  the  last  chart  of  the  North 
Atlantic,  published  on  the  authority  of  Rear-Admiral 
Richards  in  Nov.  1870,  no  soundings  are  entered 
beyond  4,000  fathoms,  and  very  few  beyond  3,000. 

A  great  improvement  in  deep-sea  sounding,  first 
introduced  in  the  United  States  navy,  was  the  use 
of  a  heavy  weight  and  a  fine  line.  The  weight,  a 
32  or  68  lb.  shot,  is  rapidly  run  down  from  a  boat ; 
and  when  it  is  supposed  to  have  reached  the  bottom, 
w^hich  is  usually  indicated  with  tolerable  certainty  by 
a  sudden  change  in  the  rate  of  running  out  of  the 
line,  the  line  is  cut  at  the  surface,  and  the  depth 
calculated  by  the  length  of  line  left  on  the  reel. 

As  the  great  problems  of  physical  geography,  the 
strength  and  direction  of  currents,  and  the  general 
conditions  of  the  bottom  of  the  sea  began  to  acquire 
more  general  interest,  the  particles  brought  up  on  the 
*  arming '  of  the  lead  from  great  depths  were  eagerly 
sought  for  and  scrutinized ;  it  thus  became  important 
that  a  greater  quantity  should  be  procured,  enough 
at  all  events  for  the  purposes  of  chemical  and  micro- 
scopical examination.  Many  instruments  have  been 
contrived  from  time  to  time  for  this  purpose,  and  a 
vast  amount  of  information  has  been  gained  by  their 
use.  It  has  now  been  shown  that  dredging  on  a  large 
scale  is  possible  at  all  depths,  but  dredging  can  only 
be  performed  under  specially  favourable  circum- 
stances, and  requires  a  vessel  specially  fitted  at  con- 
^  Loc.  cit.  2  Lqc.  cit. 


CHAP,  v.]  DEEF-SEA  SOUNDING.  209 

siderable  expense.  We  must  still,  therefore,  depend 
mainly  upon  some  form  of  sounding  apparatus  for 
the  gradual  accumulation  of  observations  which  will 
give  us  in  time  a  consistent  idea  of  the  nature  of 
the  bottom  of  the  sea  throughout.  A  simple  instru- 
ment which  will  bring  up  a  surface  sample  of  a 
pound  or  so,  from  a  depth  of  2,000  fathoms,  with- 
•out  much  trouble  and  with  some  certainty,  is  still  a 
desideratum. 

In  the  year  1818,  Sir  John  Ross,  in  command  of 

H.M.S.   '  Isabella,'  on  a  voyage  of  discovery  for  the 

purpose  of  exploring  Baffin's  Bay,  invented  a  machine 

"  for  taking  up  soundings  from  the  bottom  of  any 

fathomable    depth,"    which   he    called    a    '  deep-sea 

clamm.'     A  large  pair  of  forceps  w^ere  kept  asunder 

by  a  bolt,  and  the  instrument  was  so  contrived  that 

on  the  bolt  striking  the  ground,  a  heavy  iron  weight 

'  slipped  down  a  spindle  and  closed  the  forceps,  which 

I  retained  within  them  a  considerable  quantity  of  the 

!  bottom,  whether  sand,  mud,  or  small  stones.^    On  the 

\  1st  of  September,   1818,    Sir  John  Boss  sounded  in 

1 1,000  fathoms,  lat.  73°  37'  N.,  long.  75°  25'  W.     The 

1  soundings  consisted  of   "  soft  mud,  in  which   there 

I  were  worms,  and,  entangled  on  the  sounding-line,  at 

the  depth  of  800  fathoms,  was  found  a  beautiful  Caput 

Medusce'!     On  the  6tli  of  September  Sir  John  Boss 

sounded    in    1,050    fathoms,    lat.    72°  23'   N.,  long. 

73°  075'  W.,  and  the  clamms  brought  up  6  lbs.  of  very 

^  A  Voyage  of  Discovery  made  under  the  Orders  of  the  Admiralty 
in  His  Majesty's  Ships  '  Isabella  '  and  '  Alexander,'  for  the  purpose  of 
exploring  Baffin's  Bay,  and  inquiring  into  the  Possibility  of  a  North- 
west Passage.  By  John  Eoss,  K.S,,  Captain  Eoyal  Navy.  London  : 
1811);  p.  178. 

P 


210 


THE  DEPTHS  OF  THE  SEA. 


[chap. 


soft  mud.  I  mention  these  soundings  thus  parti- 
cularly because  they  are  the  first  authentic  instancesMl 
of  any  quantity  of  the  bottom  having  been  brought 
up  from  such  depths.  The  clamms  were  used  with 
strong  whale  line  made  of  the  best  hemp,  2^  inches 
in  circumference.  The  weight  recommended  by  Sir 
John  Eoss  for  the  sounding  in  the  North 
Sea  is  fifty  pounds. 

One  of  the  earliest  and  certainly  not  the 
worst  of  these  miniature  dredges  is  a  simple 
modification  of  the  common  deep-sea  lead, 
the  'cup-lead*  (Eig.  37).  A  rod  of  iron 
passes  through  the  lead,  and  ends  a  few 
inches  beneath  it  in  a  conical  iron  cup. 
A  thick  bend-leather  washer  slides  freely 
on  the  rod  between  the  end  of  the  lead  and 
the  cup.  The  theory  of  this  instrument  is, 
that  as  the  lead  runs  down,  the  current  of 
water  keeps  up  the  washer,  leaving  the 
mouth  of  the  cup  free.  On  reaching  the 
ground,  the  weight  of  the  lead  drives  the 
cup  into  the  mud  or  sand,  and  the  lead  falls 
to  one  side.  When  the  lead  is  hauled  up, 
a  sample  of  the  bottom  goes  into  the  cup, 
and  is  retained  there  by  the  washer,  which 
is  pressed  down   upon  the  top  of  the  cup 


Fir,.  37. 


The  during  its  upward  journey  by  the  reversal 
of  the  current.  The  'cup-lead'  is  very 
useful  for  moderate  depths.  Twice  out  of  three 
times  it  brings  up  a  sample,  but  the  cup  is  too  open 
and  the  means  of  closing  it  are  too  crude,  and  the 
third  time  everything  is  washed  out  and  the  cup 
comes  up  perfectly  clean.     Deep  soundings  take  too 


CHAP,  v.] 


DEEP-SEA  SOUNDING. 


211 


much  time  and  are  too  valuable  to  admit    so  large 
an  average  of  losses. 


Fifj.  3S.— Brooke's  Deep-Sea  Sounding  Apparatii 


About  the  year  1854,  J.  M.  Brooke,  passed-mid- 
I  shipman  in  the  U.S.  navy,  a  clever  young  officer  who 


p  2 


212  THE  DEPTHS  OF  THE  SEA.  [chap.  v. 

was  at  the  time  doing  duty  in  the  Observatory,  pro- 
posed to  Captain  Maury  a  contrivance  by  which  the] 
shot  might  be  detached  as  soon   as  it  reached  the' 
bottom,  and  specimens  brought  up  in  its  stead.     The] 
result  of  this  suggestion  was  Brooke's  deep-sea  sound- 
ing apparatus  (Figs.  38  and  39),  of  which  all  the  morej 
recent  contrivances  have  been  to  a  great  extent  modi- 
fications and  improvements,  retaining  its  fundamental! 
principle,  the  detaching  of  the  weight.     The  instru- 
ment as  devised  by  Mr.  Brooke  is  very  simple.     Aj 
64  lb.  shot  E  is  cast  with  a  hole  through  it.     An^ 
iron  rod  a  has  a  chamber  b  at  the  lower  end,  and 
two  moveable  arms  hinged  to  the  upper  end  with 
eyes  to  fasten  two  cords  by  which  the  rod  is  sus- 
pended ;  so  that  when  the  instrument  is  hanging  free 
the  arms  are  nearly  vertical  (Fig.  38).     Each  arm 
bears  a  projecting  notched  tooth,  and  before  sounding 
the  shot  is  suspended,  with  the  rod  passing  through 
it,  in  a  canvas  or  leather  sling  c  attached  by  cords 
whose  loops  pass   over  the  teeth.     The  cup  at  the 
lower  end  of  the  rod  is  filled  with  tallow  '  arming,'  in 
which  a  chamber  has  been  made  by  pushing  in  a 
wooden  plug.     When  the  instrument  strikes,  the  end 
of  the  rod  is  driven  into  the  material  of  the  bottom, 
which  fills  the  chamber  in  the  arming,  the  two  jointed 
arms  fall  down,  the  loops  of  the  sling  are  relieved 
from  the  teeth,  and  the  rod  slips  through  the  hole  in 
the  shot  and  comes  up  alone  with  its  enclosed  sample 
of  sediment. 

In  this  simplest  and  earliest  form  Brooke's  sound- 
ing apparatus  had  some  of  the  defects  of  the  cup-lead. 
The  sample  of  the  bottom  was  too  small,  and  ran  a 
risk  of  being  washed  out  in  hauling  up.     Modifica- 


CHAP,  v.]  DEEP-SEA  SOUNDING.  213 

tions  were  soon  made.     Commander  Dayman  made 


Fig.  39.— Brooke's  Deep-Sea  Sounding  Apparatus. 

several  improvements  for  the   sounding  voyage   of 


214  THE  DEPTHS  OF  THE  SEA.  [chap.  v. 

H.M.S.  '  Cyclops'  in  1857.^  He  used  iron  wire  braces 
to  support  the  sinker,  as  these  detach  more  freely 
than  slings  of  rope ;  he  replaced  Brooke's  round-shot 
by  a  leaden  cylinder  to  diminish  the  resistance  and 
thus  increase  the  velocity  in  descending ;  and  he 
adapted  a  valve  opening  inwards,  to  the  terminal 
chamber  in  the  rod,  to  prevent  the  washing  out  of 
the  sample.  Commander  Dayman  seems  to  have 
found  the  apparatus  thus  improved  to  answer  well. 
He  used  it  throughout  his  important  survey  of  the 
*  telegraph  plateau.' 

The  '  Bull-dog '  sounding  machine  (Fig.  40)  is  now 
probably  the  most  generally  known  of  these  dredging- 
leads.  This  instrument  is  an  adaptation  of  Sir  John 
Boss'  deep-sea  clamms,  with  the  addition  of  Brooke's 
principle  of  the  disengaging  weight.  It  was  invented 
during  the  famous  sounding  voyage  of  H.M.S.  '  Bull- 
dog' in  the  year  1860,  and  Sir  Leopold  M'Clintock 
gives  the  chief  credit  of  its  invention  to  the  assistant- 
engineer  on  board,  Mr.  Steil.2  A  pair  of  scoops  A 
close  upon  one  another  scissor  wise  on  a  hinge,  and  have 
two  pairs  of  appendages  b,  which  stand  to  the  open- 
ing and  closing  of  the  scoops  in  the  relation  of  scissor 
iiandles.  This  apparatus  is  permanently  attached  to 
the  sounding-line  by  the  rope  r,  which  in  the  figure 
is  represented  hanging  loose,  and  which  is  fixed  to 

1  Deep-Sea  Soundings  in  the  North  Atlantic  Ocean,  between 
Ireland  and  Newfoundland,  made  in  H.M.S.  '  Cyclops/  Lieut.-Com- 
mander  Joseph  Dayman,  in  June  and  July  1857.  Published  by 
order  of  the  Lords  Commissioners  of  the  Admiralty.     London  :  1858. 

2  Eemarks  illustrative  of  the  Sounding  Yoyage  of  H.M.S.  'Bull- 
dog' in  1860;  Captain  Sir  Leopold  M'Clintock  commanding.  Pub- 
lished by  order  of  the  Lords  Commissioners  of  the  Admiralty. 
London:   1861. 


CHAP.  V.J 


BEEF -SEA  SOUNDING. 


215 


Fig.  40.— Tlie  'Bull-dog'  Sounding  Machine. 


216  THE  DEPTHS  OF  THE  SEA.  [chap.  v. 

the  spindle   on  which  the   cups  turn.     Attached  to 
the  same  spindle  is  the  rope  d,  which  ends  above  in 
an  iron  ring,     e  represents  a  pair  of  tumbler  hooks, 
fastened  likewise  to  the  end  of  the   sounding-line; 
c  a  heavy  leaden  or  iron  weight,  with  a  hole  through 
it  wide  enough  to  allow  the  rope  d  with  its  loop  and 
ring  to  pass  freely ;  and  b,  a  strong  india-rubber  band 
which  passes  round  the  handles  of  the  scoops.    In  the 
figure  the  instrument  is  represented   as   it   is    sent 
down  and  before  it  reaches  the  bottom.     The  weighty 
c  and  the  scoops  a  are  now  suspended  by  the  rope  d, 
whose  ring  is  caught  by  the  tumbler  hooks  e.     Th( 
elastic  ring  b  is  in  a  state  of  tension,  ready  to  draw; 
together  the  scoop  handles  and  close  the  scoops,  but; 
it  is  antagonized  by  the  weight  c,  which,  pressing 
down  into  a  space  between  the  handles,  keeps  them 
asunder.     The  moment  the  scoops  are  driven  into  th( 
ground  by  the  weight,  the  tension  on  the  rope  d  it 
relaxed,  the  tumblers  fall  and  release  the  ring,  an( 
the  weight  falls  and  allows  the  elastic  band  to  clos( 
the  scoops  and  to  keep  them  closed  upon  whatevei 
they   may   contain;    the   rope   D    slips   through   th( 
Aveight,  and  the  closed  scoops  are  drawn  up  by  the 
rope  F.     This  is  a  pretty  idea,  and  an  ingenious  am 
elegant  apparatus,  but  it  is  rather  complicated, 
have  never  seen  it  in  use,  but  I  should  fear  that  th( 
observer  might  often  be  thwarted  by  the  scoops  falli 
ing  in  a  wrong  direction,  or  by  pebbles  getting  int( 
the  hinges  and  preventing  their  closing  thoroughly. 
The  simpler  all  these  things  are  the  better. 

We  used  in  our  trip  in  the  'Lightning'  in  1868  ai 
instrument  (Fig.  41)  which  at  first  sight  scarceb 
looks  promising  from  its  apparent  want  of  compact- 


;iTAr.  v.] 


DEEF-ShA  SOUNmKG. 


217 


ness,  but  I  will  say  this  for  the 
*  Fitzgerald'  sounding  apparatus 
that  I  never  knew  it  fail ;  and 
we  were  obliged,  unfortunately 
for  ourselves,  to  try  it  fre- 
quently in  very  bad  weather 
and  under  most  unfavourable 
circumstances.  The  sounding- 
line  ends  in  a  loop  passing 
through  an  eye  in  the  centre  of 
a  bar  of  iron  r.  The  bar  ter- 
minates at  one  end  in  a  claw 
and  at  the  other  in  a  second 
eye,  to  which  a  chain  is  at- 
tached. A  scoop  A,  with  a 
sharp,  spade-like  lip,  is  fixed  to 
a  long  and  rather  heavy  iron 
rod  D,  with  an  expanded  rudder- 
shaped  end  to  steady  it  in  pass- 
ing quickly  through  the  water, 
and  beneath  this  an  eye,  which 
fits  the  claw  of  the  bar  f.  A 
door  B  fits  the  scoop  to  which 
it  is  hinged,  and  it  is  also 
hinged  to  the  arm  c,  which, 
when  held  in  a  vertical  posi- 
tion, keeps  it  open.  The  arm  c 
is  attached  by  the  chain  to  the 
eye  in  the  bar  e,  and  the  arm 
and  chain  correspond  in  length 
to  the  rod  d.  Two  teeth  ee 
project  from  d,  and  on  these  are 
hung    a    heavy     weight.      The 


Fig.  41. 


-Tiie  •  Fitzgerald ' 
Machine. 


Sounding 


218 


7 HE  DEPTHS  OF  THE  SEA. 


[chap.  v. 


apparatus  is  so  adjusted,  that  when 
the  weight  is  attached  and  the  instru- 
ment hanging  ready  for  use,  as  repn 
sented  in  the  figure,  the  rod  f  main] 
tains  a  horizontal  position.  When  th< 
instrument  strikes  the  ground,  th^ 
tension  on  the  har  f  is  relieved,  th^ 
weight  draws  the  rod  d  off  the  clai 
and  slips  off,  at  the  same  time  filling 
the  scoop.  When  hauling  up,  all  the 
instrument  falls  into  a  nearly  vertical 
line,  and  the  scoop  comes  up  fall  in 
the  middle,  the  weight  of  d  keeping 
its  mouth  closed  up  against  its  lid. 

The  apparatus  used  during  the 
cruise  of  the  '  Porcupine,"  where 
sounding  was  carried  on  to  the  utmost 
attainable  accuracy  and  at  great 
depths,  was  a  somewhat  elaborate 
modification  of  Brooke's  sounding 
machine  which  had  been  previously 
employed  by  Captain  Shortland  in 
the  voyage  of  H.M.S.  '  Hydra,'  sound- 
ing across  the  Arabian  Gulf  prepara- 
tory to  laying  the  Indian  Cable. 

This  special  modification,  which  cer- 
tainly answered  remarkably  well,  ap- 
pears to  have  been  due  entirely  to 
Mr.  Gibbs,  the  blacksmith  on  board 
the   vessel.^      We    christened    it    the 

^  Sounding  Voyage  of  H.M.S.  *  Hydra,'  Captain 
P.  F.  Shortland,  1868.     Published  by  order  of  the 
^'sounto'^  Machine '** '    ^"^^^^  Commiss.  of  the  Admiralty.    London  :  1869. 


CHAP,  v.]  DEEP-SEA  SOUNDING.  219 

*  Hydra,'  in  recognition  of  its  inventor  and  of  the 
vessel  in  which  it  was  first  used. 

The  axis  of  the  -  Hydra  '  (Pig.  42)  is  a  strong  brass 
tube,  which  unscrews  into  four  chambers.  The  three 
lowest  of  these  are  closed  above  by  conical  valves 
opening  upwards,  but  not  fitting  absolutely  tightly,  so 
as  to  allow  a  little  water  to  pass ;  and  the  lowest 
chamber  b  is  closed  by  a  butterfly  valve  also  open- 
ing upwards.  The  upper  (fourth)  chamber  a  contains 
a  piston,  and  the  piston-rod  c  is  continued  upwards 
into  a  rod  which  ends  in  the  ring  to  which  the 
soimding-line  is  attached.  The  upper  chamber  in 
which  the  piston  works  has  a  large  hole  on  either 
side  about  the  middle  of  its  length,  and  a  small  hole 
passes  through  the  piston  itself.  Projecting  from  the 
upper  part  of  the  rod  there  is  a  notched  tooth  D,  and 
over  the  tooth  passes  an  arched  steel  spring,  with 
a  slit  which  allows  the  tooth  to  pass  through  its 
centre,  and  its  two  ends  fastened  moveably  to  the 
rod.  When  the  spring  is  forcibly  pushed  back,  it 
allows  the  tooth  with  its  notch  to  protrude  through 
the  central  slit.  The  weight  consists  of  three  or  four 
cylinders  of  iron  f,  toothed  and  notched  so  as  to  fit 
into  one  another  and  make  one  mass.  The  weight 
used  in   the   '  Porcupine '    was   from   two   to   three 

i  hundredweight,  according  to  the  depth.  The  weight 
is  suspended  by  an  iron  wire  sling  which  passes  over 

j  the  notched  tooth,  the  spring  having  been  pressed 
back.  The  weight  is  amply  sufficient  to  retain  the 
spring  in  that  position. 

The  figure  represents  the  instrument  prepared  to  let 
go,  the  whole  weight  suspended  from  the  ring  at  the 
top  of  the  piston-rod,  which  is  thus  fully  drawn  out 


220  THE  DEPTHS  OF  THE  SEA.  [chap. 

of  its  cylinder.  As  the  instrument  runs  down  th< 
water  passes  freely  through  the  tube  and  valves,  an< 
pours  out  by  the  holes  in  the  wall  of  the  cylindei 
When  it  touches  the  ground  the  piston  is  pulh 
down  by  the  weight,  but  its  progress  is  somewhat 
arrested  by  the  water  in  the  lower  part  of  the 
cylinder,  which  can  only  escape  slowly,  thus  giving 
the  weight  time  to  force  the  terminal  chamber  with 
the  butterfly  valves  into  the  ground.  The  weights 
then  rest  upon  the  bottom  and  relieve  the  spring 
which  throws  the  sling  off  the  tooth.  The  tube 
comes  up  free  with  all  the  valves  closed,  and  the  last 
chamber  filled  with  the  substance  of  the  bottom,  and 
the  other  chamber  with  bottom  water. 

In  the  skilful  hands  of  Captain  Calver  the  *  Hydra' 
never  once  failed,  and  from  the  great  weight  used  it 
is  admirably  suited  for  accurate  soundings  in  deep 
water ;  but  it  is  somewhat  complicated,  and  it  brings 
up  very  small  samples  of  the  bottom.  In  the  case  of 
the  cruise  of  the  '  Porcupine,'  where  the  large  dredge 
was  sent  down  at  almost  every  sounding-station,  this 
was  of  little  consequence ;  but  where  dredging  is  im- 
practicable, and  all  information  as  to  the  condition  of 
the  bottom  must  be  got  from  soundings,  some  simple 
adaptation  of  the  '  Bull-dog  '  scoops  or  the  Fitzgerald 
apparatus  would  certainly  have  a  great  advantage. 

During  the  cruise  of  the  '  Porcupine '  in  1869 
soundings  were  taken  with  the  utmost  care  at  ninety 
stations,  and  in  1870  at  sixty-seven  stations,  and  on 
every  occasion  the  operation  was  conducted  by  Capt. 
Calver  himself,  whose  great  experience  on  the  sur- 
veying service  was  in  itself  a  guarantee  of  the  greatest 
possible  accuracy.     Captain  Calver  told  me  that  on 


iiAP.  v.]  DEEP-SEA  SOUNDING.  221 

every  occasion,  even  at  the  greatest  depths,  he  felt 
distinctly  the  shock  of  the  arrest  of  the  weight  upon 
the  bottom  communicated  to  his  hand.  A  careful 
sounding  was  always  taken  immediately  before  letting 
go  the  dredge.  I  will  take  as  an  example  the  sound- 
ing which  determined  the  depth  of  the  deepest  haul 
of  the  dredge  yet  made,  in  2,435  fathoms  in  the  Bay 
of  Biscay  on  the  22nd  of  July,  1869,  and  describe 
the  modus  opermidi. 

The  '  Porcupine '  was  provided  at  Woolwich  with 
an  admirable  double  cylinder  donkey-engine  of  12- 
horse  power  (nominal),  placed  on  the  deck  amidships, 
with  a  couple  of  surging  drums.  This  little  engine 
was  the  comfort  of  our  lives ;  nothing  could  exceed 
the  steadiness  of  its  working  and  the  ease  with  which 
its  speed  could  be  regulated.  During  the  whole  ex- 
pedition it  brought  in  with  the  ordinary  drum,  the 
line,  whether  sounding-line  or  dredge-rope,  with 
almost  any  weight,  at  a  uniform  rate  of  a  foot  per 
second.  Once  or  twice  it  was  over-strained,  and  then 
we  pitied  the  willing  little  thing  panting  like  an  over- 
taxed horse ;  and  sometimes  we  put  on  a  small  drum 
for  very  hard  work,  gaining  thereby  additional  power 
at  some  expense  of  speed. 

Two  powerful  derricks  were  rigged  for  sounding 
and  dredging  operations,  one  over  the  stern  and  one 
over  the  port  bow.  The  bow  derrick  was  the  stronger, 
and  we  usually  found  it  the  more  convenient  to 
dredge  from.  Sounding  was  most  frequently  carried 
on  from  the  stern.  Both  derricks  were  provided  with 
accumulators,  accessory  pieces  of  apparatus  which 
we  found  of  great  value.  The  block  through  which 
the  sounding-line  or  dredging-rope   passed  was  not 


222  THE  DEfTHS  OF  THE  SEA.  [chap.  v._l 

attached  directly  to  the  derrick,  but  to  a  rope  which 
passed  through  an  eye  at  the  end  of  the  spar,  and_| 
was  fixed  to  a  '  bitt '  on  the  deck.  On  a  bight  ofl| 
this  rope  between  the  block  and  the  '  bitt '  the  accu- 
mulator was  lashed.  This  consists  of  thirty  or  forty 
or  more  of  Hodge's  vulcanized  india-rubber  springs 
fastened  together  at  the  two  extremities,  and  kept 
free  from  one  another  by  being  passed  through 
holes  in  two  round  wooden  ends  like  the  heads  of 
churn- staves.  The  loop  of  the  rope  is  made  long 
enough  to  permit  the  accumulator  to  stretch  to  double 
or  treble  its  length,  but  it  is  arrested  far  within  its 
breaking  point.  The  accumulator  is  valuable  in  the 
first  place  as  indicating  roughly  the  amount  of  strain 
upon  the  line;  and  in  order  that  it  may  do  so  witli 
some  decree  of  accuracy  it  is  so  arranged  as  to  play 
along  the  derrick,  which  is  graduated  from  trial  to  the 
number  of  cwts.  of  strain  indicated  by  the  greater  or 
less  extension  of  the  accumulator ;  but  its  more  im- 
portant function  is  to  take  off  the  suddenness  of  the 
strain  on  the  line  when  the  vessel  is  pitching.  The 
friction  of  one  or  two  miles  of  cord  in  the  water  is  so 
great  as  to  prevent  its  yielding  freely  to  a  sudden  jerk 
such  as  that  given  to  the  attached  end  when  the 
vessel  rises  to  a  sea,  and  the  line  is  apt  to  snap.  A 
letting-go  frame  like  that  used  on  board  the  '  Hydra,' 
a  board  with  a  slit  through  which  tlie  free  end  of  the 
sounding  machine  passed,  and  which  supported  the 
weights  wliile  the  instrument  was  being  prepared,  was 
fitted  under  the  stern  derrick.  The  sounding  instru- 
ment  was  the  '  Hydra,'  weighted  with  336  lbs.  The 
sounding-line  was  wound  amidships  just  abaft  the 
donkey-engine  on  a  large  strong  reel,  its  revolution 


■HAP.  v.] 


DEEP-SEA  SOb'NniJSiG. 


223 


commanded  by  a  brake.  The  reel  held  about  4,000 
fathoms  of  medium  No.  2  line  of  the  best  Italian 
hemp,  tlie  No.  of  threads  18,  the  weight  per  100 
fathoms  12  lbs.  8  ozs.,  the  circumference  0*8  inch,  and 
the  breaking  strain,  dry,  1,402  lbs.,  soaked  a  day 
1,211  lbs.,  marked  for  50,  100,  and  1,000  fathoms. 

The  weather  was  remarkably  clear  and  fine ;  the 
wind  from  the  north-west,  force  =  4 ;  the  sea  mode- 
rate, with  a  slight  swell  from  the  north-west.  We 
were  in  lat.  47°  38^  N.,  long.  12°  08'  W.,  at  the 
mouth  of  the  Bay  of  Biscay,  about  200  miles  to  the 
west  of  Ushant.  The  sounding  instrument,  with  two 
Miller- Casella  thermometers  and  a  water  bottle 
attached  a  fathom  or  two  above  it,  was  cast  off  the 
letting- go  frame  at  2h.  44m.  20s.  p.m.  The  line  was 
run  off  by  hand  from  the  reel  and  given  to  the 
weight  as  fast  as  it  would  take  it,  so  that  there  might 
not  be  the  slightest  check  or  strain.  The  following 
table  gives  the  absolute  rate  of  descent : — 


Fathoms. 

Time. 

! 
Interval.  \ 

m.    s.   1 

Fathoms. 

Time. 

Interval. 

h.  m.  s. 

h. 

m.  S. 

111.  s. 

0 

2  44  20 

— 

1300 

2 

58  5 

1  23 

100 

2  45  5 

0  45 

1400 

2 

59  37 

1  32 

,   200 

2  4.5  45 

0  40  1 

1500 

3 

1  9 

1  32 

1   300 

2  46  30 

0  45 

1600 

3 

2  42 

1  33 

400 

2  47  25 

0  55 

1700 

3 

4  19 

1  37 

500 

2  48  15 

0  50 

1800 

3 

6  6 

1  47 

600 

2  49  15 

1  0  ; 

1900 

3 

7  53 

1  47 

700 

2  50  24 

1  9 

2000 

3 

9  40 

1  47 

800 

2  51  23 

0  59 

2100 

3 

11  29 

1  49 

1   900 

2  52  45 

1  22 

2200 

3 

13  24 

1  55  i 

1  1000 

2  54  0 

1  15  ^ 

2300 

3 

15  23 

1  59 

'  1100 

2  55  21 

1  21 

2400 

3 

17  15 

1  52 

1200 

2  56  42 

1  21 

2435 

3 

17  55 

0  40 

224  THE  DEFTHS  OF  THE  SEA.  [chap.  v. 

In  this  case  the  timing  was  only  valuable  as  cor- 
roborating other  evidence  of  the  accuracy  of  the 
sounding,  for  even  at  this  great  depth,  nearly  three 
miles,  the  shock  of  the  arrest  of  the  weight  at  the 
bottom  was  distinctly  perceptible  to  the  commander, 
who  passed  the  line  through  his  hand  during  the 
descent.  This  was  probably  the  deepest  sounding 
which  had  been  taken  up  to  that  time  which  was 
perfectly  reliable.  It  was  taken  under  unusually 
favourable  conditions  of  weather,  with  the  most 
perfect  appliances,  and  with  consummate  skill.  The 
whole  time  occupied  in  descent  was  33  minutes 
35  seconds ;  and  in  heaving  up,  2  hours  2  minutes. 
The  cylinder  of  the  sounding  apparatus  came  up 
filled  with  fine  grey  Atlantic  ooze,  containing  a  con- 
siderable proportion  of  fresh  shells  of  Glohigerina, 
The  two  Miller- Casella  thermometers  registered  a 
minimum  temperature  of  2°* 5  C. 

Various  attempts  have  been  made  to  devise  an 
instrument  which  should  determine  accurately  the 
amount  of  vertical  descent  of  the  lead  by  self-regis- 
tering machinery.  The  most  successful  apparatus  for 
this  purpose,  and  the  one  most  in  use  is  *  Massey's 
sounding-machine.'  This  instrument,  in  its  latest  and 
most  improved  form,  to  be  used  with  the  common 
lead,  is  shown  in  Eig.  43.  Two  thimbles  ff  pass 
through  the  two  ends  of  the  heavy  oval  brass  sbield 
A  a;  to  the  upper  of  these  the  sotinding-line  is 
attached,  and  to  the  lower  the  weight  at  about  half 
a  fathom  .from  the  machine.  A  set  of  four  brass 
vanes  or  wings  b  are  soldered  obliquely  to  an  axis 
in  such  a  position  that  as  the  machine  descends  the 
axis  revolves  by  the  pressure  of  the  water   against 


CHAP,  v.] 


DEEP-SEA  SOUNDING. 


225 


the  vanes.  The  revolving  axis  communicates  its 
motion  to  the  indices  on  the  dial-plate  c,  which  are 
so  adjusted  that  the  index  on  the  right-hand  dial 
passes    through    a    division    for    every    fathom    of 


Fig.  43. — '  Massey's  '  Sounding  Machine. 

vertical  descent,  whether  quick  or  slow,  and  makes 
an  entire  revolution  for  15  fathoms,  while  the  left- 
hand  index  passes  through  a  division  on  the  circle  for 
15  fathoms,  and  makes  an  entire  revolution  during 

Q 


226  THE  DEPTHS  OF  THE  SEA.  [chap.  vJ 

a   descent  of  225  fathoms.     Where   greater   depths! 
are  required  it   is   only   necessary    to    add   another! 
dial  and  index.     Tliis  sounding  instrument  answers! 
very  well  in  moderately  deep  water,  and  is  extremely 
valuable   for   checking    soundings   by   the   ordinary 
method,    Avhere   deep  currents  are   suspected,  as   it 
ought  to  register   vertical   descent  only.     It  is  not 
satisfactory  in  very  deep  water,  and  its  uncertainty 
is  shared  apparently  by   all   instruments  involving 
metal  wheel-work.     It  is  difiB.cult  to  tell  the  reason. 
The  machinery  seems  to  get  jammed  in  some  way 
under  the  enormous  pressure  of  the  water. 

The  '  Massey's  sounding-machine  '  in  common  use 
is  somewhat  different  from  the  *  shield '  instrument 
described  and  figured  above.  It  is  constructed  oh. 
precisely  the  same  principle,  but  it  is  bolted  to  a 
special  form  of  sounding  lead,  and  is  thus  somewhat 
more  cumbrous. 

Besides  the  increasins^  attention  which  has  been 
paid  of  late  years  to  all  subjects  of  scientific  interest, 
and  especially  to  those  connected  with  physical  geo- 
graphy, the  conditions  of  the  depths  of  the  sea,  the 
nature  of  the  bottom,  the  force  and  direction  of  deep 
currents,  the  temperature  at  great  depths,  and,  in 
fact,  all  the  conditions  affecting  the  sea  bottom, 
have  lately  acquired  great  practical  importance  in 
connection  with  telegraphic  communication  by  ocean 
cables. 

The  Atlantic  Ocean,  with  the  accessible  portions 
of  the  Arctic  Sea,  has  naturally,  from  the  relation  in 
which  it  stands  to  the  first  maritime  and  commercial 
nations  of  the  present  period,  been  the  most  carefully 
surveyed ;   and  as  it  appears  to  contain  depths  nearly 


criAP.  V.J  DEEP-SEA  SOUNDING.  227 

if  not  quite  as  great  as  any  to  be  found  in  tlie  other 
ocean  basins,  it  may  probably  be  taken  as  a  fair 
example  of  ordinary  conditions.  It  is  open  from 
pole  to  pole,  and  thus  participates  in  all  conditions 
of  climate,  and  it  communicates  freely  with  the 
other  seas.  We  have  still  but  scanty  information 
about  the  beds  of  the  Indian,  the  Antarctic,  and  the 
Pacific  oceans,  but  the  few  observations  which  have 
hitherto  reached  us  seem  to  indicate  that  neither  is 
the  depth  extreme  in  these  seas,  nor  does  the  nature 
of  the  bottom  differ  greatly  from  what  w^e  find  nearer 
home.  The  Mediterranean  —  a  closed  cul-de-sac 
almost  cut  off  from  the  general  ocean — is  under 
most  peculiar  circumstances,  which  will  be  discussed 
hereafter.  The  general  result  to  which  we  are  led 
l)y  the  careful  and  systematic  deep-sea  soundings 
which  have  been  undertaken  of  late  years  by  our 
own  Admiralty  and  by  the  American  and  Swedish 
Governments,  is  that  the  depth  of  the  sea  is  not  so 
great  as  was  at  one  time  supposed.  I  have  already 
mentioned  that  in  some  of  the  earlier  sounding  expe- 
ditions enormous  depths  were  registered  from  various 
parts  of  the  Atlantic,  and  I  have  also  mentioned  the 
reasons,  depending  chiefly  upon  defective  appliances, 
why  many  of  these  soundings  are  now  considered  un- 
trustworthy. Lieutenant  Berryman,  of  the  U.S.  brig 
'  Dolphin,'  reported  4,580  fathoms  (27,480  feet),  equal 
to  the  height  of  Dwalagiri,  in  lat.  41°  1'  N.,  long. 
49°  23'  W.,  half-way  between  New  York  and  the 
A9ores;  'no  bottom'  at  4,920  fathoms  (29,520  feet), 
deeper  than  the  height  of  Deodunga,  the  higliest 
peak  in  the  world,  in  lat.  38°  3'  N.,  long.  67°  14'  W.; 
and  'no  bottom'  at    6,600   fathoms    (39,600   feet), 

Q  2 


228  THE  DEPTHS  OF  THE  SEA.  [chap.  v. 

lat.  32°  55'  N.,  long.  47°  58'  W.,  indicating  a  cliasni 
between  the  coast  of  America  and  the  Western 
Islands,  which  might  easily  engulph  the  whole  range 
of  the  Himalayas.  This  space  probably  represents 
the  deepest  part  of  the  North  Atlantic ;  but  there  is 
little  doubt  that  these  depths  are  greatly  exagge- 
rated. The  average  depth  of  the  ocean  bed  does  not 
appear  to  be  much  more  than  2,000  fathoms  (12,000 
feet),  about  equal  to  the  mean  height  of  the  elevated 
table  lands  of  Asia. 

The  thin  shell  of  water  which  covers  so  much  of 
the  face  of  the  earth  occupies  all  the  broad  general 
depressions  in  its  crust,  and  it  is  only  limited  and 
more  abrupt  prominences  which  project  above  its 
surface  as  masses  of  land  with  their  crowning  pla- 
teaux and  mountain  ranges.  The  Atlantic  Ocean 
covers  30,000,000  of  square  miles  and  the  Arctic  Sea 
3,000,000,  and  taken  together  they  almost  exactly 
equal  the  united  areas  of  Europe,  Asia,  and  Africa 
— the  whole  of  the  old  world ;  and  yet  there  seem 
to  be  few  depressions  in  its  bed  to  a  greater  depth 
than  15,000  or  20,000  feet— a  little  more  than  the 
height  of  Mont  Blanc — and  except  in  the  neigh- 
bourhood of  the  shores  there  is  only  one  very 
marked  mass  of  mountains,  the  volcanic  group  of 
the  A9ores. 

The  central  and  southern  parts  of  the  Atlantic 
appear  to  be  an  old  depression,  probably  at  all  events 
coseval  with  the  deposition  of  the  Jurassic  forma- 
tions of  Europe,  and  throughout  these  long  ages 
the  tendency  of  that  great  body  of  water  has  no 
doubt  been  to  ameliorate  the  outlines,  softening  down 
asperities  by  the  disintegrating  action  of  its  waves 


CHAP,  v.]  DEEP-SEA  SOUNDING.  229 

and  currents,  and  filling  up  hollows  by  drifting  about 
and  distributing  their  materials. 

The  first  careful  surveys  of  the  Atlantic,  in  which 
great  depths  were  determined  with  considerable  accu- 
racy, are  the  cruises  of  Lieut. -Commanding  Lee,  in 
the*^  U.S.  brig  '  Dolphin '  (1851-52),  and  of  Lieut- 
Commanding  O.  H.  Berryman,  in  the  same  vessel 
in  1852-53;  but  the  sounding  voyage  in  which 
modern  appliances  were  first  employed  with  perfect 
accuracy  with  a  practical  object  was  that  of  Lieu- 
tenant Berryman  in  1856,  in  the  U.S.  steamer 
'Arctic,'  in  which  twenty-four  deep-sea  soundings 
were  taken  with  the  Brooke's  and  Massey's  sounding 
machines  on  a  great  circle  between  St.  John's,  New- 
foundland, and  Yalentia  in  Ireland,  with  a  view 
to  the  laying  of  the  first  cable.  The  same  ground 
was  gone  over  by  Lieutenant  Dayman,  in  H.M.S. 
'Cyclops,'  in  June  and  July  1857,  and  thirty-four 
soundings  were  taken,  the  depth  being  estimated  by 
Massey's  sounding-machine  and  a  modification  of 
Brooke's  machine  already  described.  The  next  im- 
portant sounding  expedition  was  that  of  Commander 
Dayman,  in  H.M.S.  *  Gorgon,'  from  Newfoundland  to 
the  A9ores,  and  thence  to  England.  The  depths 
were  taken  in  this  case  with  a  lead  usually  188  lbs. 
in  weight  which  was  lost  at  each  cast,  and  alba- 
core  line  with  a  breaking  strain  of  420  lbs.  Only 
on  one  occasion,  about  a  third  of  the  way  from  the 
A9ores  to  England,  a  cup-lead  was  let  go,  attached 
to  a  stronger  line,  in  1,900  fathoms,  and  came  up  half 
filled  with  grey  ooze. 

Another  route  for  a  telegraph  cable  having  been  pro- 
posed, H.M.S.  '  Bull-dog'  started  in  July  1860,  under 


130 


THE  DEPTHS  OF  THE  SEJ. 


[chap. 


the  command  of  Captain  Sir  Leopold  M'Clintock,  and 
took  depths  between  the  Fgeroe  Islands  and  Iceland, 
and  thence  to  Greenland  and  Labrador.  The  sound- 
ings were  taken  first  by  cod-line  and  an  iron  sinker 
of  about  1  cwt.,  the  line  and  sinker  being  cut  off  at 
each  operation ;  and  the  sounding  was  then  usually 
repeated  with  the  'Eull-dog'  sounding-machine,  with 
which  large  samples  of  the  bottom  were  procured. 
A  diary  of  this  voyage  was  kept  by  Dr.  Wallich, 
Naturalist  to  the  Expedition,  and  was  afterwards 
published  by  him  as  part  of  the  extremely  important 
memoir  on  the  North  Atlantic  sea-bed,  to  which 
I  have  already  referred.  Some  further  questions 
having  arisen  as  to  the  best  line  to  be  taken  by 
an  Atlantic  telegraph  cable.  Captain  Hoskyn,  E.N., 
Avas  despatched  in  the  '  Porcupine '  to  examine  the 
curious  dip  from  550  to  1,750  fathoms,  described 
by  Captain  Dayman  in  1857  as  occurring  about  170 
miles  west  of  A^alentia.  One  important  result  of  this 
cruise  was  the  discovery  of  the  '  Porcupine '  Bank, 
about  120  miles  west  from  Gal  way  Pay,  with  a  mini- 
mum depth  of  82  fathoms. 

Towards  the  latter  part  of  the  year  1868  H.M.S. 
'Gannet,'  Commander  W.  Chimmo,  E;.N.,  wasj 
ordered  by  the  Admiralty  to  define  during  her 
homeward  voyage  from  the  West  India  Station] 
the  northern  limits  of  the  Gulf  Stream,  and  to] 
take  deep  soundings  and  temperatures.  Thirteen' 
soundings  were  taken  with  the  Brooke's  machine] 
over  an  area  of  upwards  of  10,000  square  miles 
from  Sable  Island  (lat.  43^  20'  N.,  long.^60°  W.),  at] 
depths  varying  from  80  to  2,700  fathoms. 

Por  many  years  past  the  American  Governmeni 


CHAP,  v.]  -DEPJP-SEA  SOUNDING.  231 

have  been  prosecuting  a  most  careful  and  elaborate 
survey  of  their  coast-line ;  and  latterly  the  Coast 
Survey,  under  the  late  Professor  Bache  and  the  pre- 
sent energetic  head  of  the  Bureau,  Professor  Pierce, 
has  pushed  its  operations  into  deep  water,  particu- 
larly in  the  Gulf-stream  region  north-westwards  of 
the  Strait  of  Plorida.  Dredging  operations  have 
been  conducted  most  successfully  under  Count  Pour- 
tales,  and  it  will  be  seen  hereafter  that  his  results 
are  a  valuable  complement  and  corroboration  of  our 
own.  The  Swedish  Government  has  twice  executed 
careful  soundings  in  the  sea  between  Spitzbergen  and 
Greenland  and  to  the  south-west  of  Spitzbergen ;  in 
1860  under  the  direction  of  Otto  Thorell,  and  in 
1868  through  the  Swedish  Arctic  Exploring  Expe- 
dition under  Captain  Count  von  Otter  of  the  Boyal 
Swedish  steamer  '  Sophia/  In  1869  the  Swedish 
corvette  '  Josephine '  sounded  and  dredged  in  the 
North  Atlantic,  taking  soundings  to  the  depth  of 
upwards  of  3,000  fathoms,  and  discovered  the  '  Jose- 
phine Bank,'  with  a  minimum  depth  of  102  fathoms, 
in  ]at.  36°  45'  N.,  long.  14°  10' A¥.  to  the  north-west 
of  the  Strait  of  Gibraltar.  The  North-German  Polar 
expeditions  greatly  increased  our  knowledge  of  the 
Spitzbergen  and  the  Greenland  Seas  ;  and  finally, 
on  December  20th,  1870,  the  American  nautical 
school-ship  'Mercury,'  Captain  P.  Giraud,  crossed  the 
Tropical  Atlantic  to  Sierra  Leone,  which  she  reached 
on  the  14th  of  Eebruary,  1871.  She  left  Sierra 
Leone  on  Eebruary  21st,  and  soundings  and  other 
observations  were  continued  till  she  reached  Havan- 
nah  on  the  13th  of  April.  The  object  of  this  ex- 
pedition   and   the    character   of    the   observers    are 


232  THE  DEPTHS  OF  THE  SEA.  [chap.  v. 

singular  and  instructive.  It  seems  that  the  '  Mer- 
cury '  is  a  vessel  belonging  to  the  Commissioners  in 
charge  of  the  hospitals  and  prisons  of  New  York,  and 
it  is  employed  for  the  purpose  of  training  boys, 
committed  by  the  magistrates  for  vagrancy  and  slight 
misdemeanours,  to  become  thorough  seamen.  One 
important  part  of  the  training  in  this  ship  is  that 
she  makes  long  cruises,  and  the  boys  are  thus  fitted 
quickly  to  enter  into  the  service  of  the  navy  or  the 
mercantile  marine.  In  the  present  cruise,  the  Com- 
missioners, desiring  to  promote  the  education  of  the 
lads  and  to  advance  the  interests  of  science  as  much 
as  lay  in  their  power,  instructed  the  captain  to  obtain 
a  series  of  soundings  on  the  line  of  or  near  the 
equator  from  the  coast  of  Africa  to  the  mouth  of  the 
Amazon,  and  to  observe  the  set  of  the  surface  currents 
and  the  temperature  of  the  water  at  various  depths. 

The  Commissioners  report  most  favourably  of  this 
mode  of  training,  which  is  now  being  so  generally 
adopted  in  this  country.  For  such  boys  the  adven- 
turous life  has  a  special  charm,  and,  "  instead  of 
growing  up  to  be  a  curse  to  the  community,  they 
are  made  into  valuable  men."  Two  hundred  and 
fifty  scapegraces  were  sent  out  on  this  voyage,  and 
on  the  return  of  the  ship,  in  the  opinion  of  the 
captain  100  of  these  were  capable  of  discharging  the 
duties  of  ordinary  seamen. 

Brooke's  detaching  sounding  apparatus  was  used 
in  the  '  Mercury,'  and  in  the  report  of  the  scientific 
results  of  the  voyage,  which  w  as  drawn  out  by  Pro- 
fessor Henry  Draper  of  New  York,  a  diagram  of  the 
bed  of  the  Atlantic  at  the  twelfth  parallel  is  intro- 
duced, based  on  fifteen    soundings.     It  shows  that,  ■ 

'  J 


CHAP,  v.]  DEEP-SEA  SOUNDING.  233 

''  parting  from  the  African  coast,  the  bed  of  the 
ocean  sinks  very  rapidly.  A  couple  of  degrees  west 
of  the  longitude  of  Cape  Yerde  the  soundings  are 
2,900  fathoms.  From  this  point  the  mean  depth 
across  the  ocean  may  be  estimated  at  about  2,400 
fathoms,  but  from  this  there  are  two  striking 
departures — first,  a  depression,  the  depth  of  which 
is  3,100  fathoms ;  and,  second,  an  elevation,  at  which 
the  soundings  are  only  1,900,  the  general  result  of 
this  being  a  deep  trough  on  the  African  side  and  a 
narrower  and  shallower  trough  on  the  American."^ 

lleferring  to  the  chart  (PL  VII.),  in  which  the 
greater  depths  are  indicated  by  the  deeper  shades  of 
blue,  a  shade  to  every  1,000  fathoms ;  in  the  Arctic 
Sea  there  is  deep  water  ranging  to  1,500  fathoms  to 
the  west  and  south-west  of  Spitzbergen.  Extending 
from  the  coast  of  Norway  and  including  Iceland,  the 
Fseroe  Islands,  Shetland  and  Orkney,  Great  Britain 
and  Ireland,  and  the  bed  of  the  North  Sea  to  the 
coast  of  France,  there  is  a  wide  plateau  on  which  the 
depth  rarely  reaches  500  fathoms,  but  to  the  west  of 
Iceland  and  communicating  doubtless  with  the  deep 
water  in  the  Spitzbergen  Sea  a  trough  500  miles  wide 
and  in  some  places  nearly  2,000  fathoms  deep, 
curves  along  the  east  coast  of  Greenland.  This  is 
the  path  of  one  of  the  great  Arctic  return  currents. 

^  Cruise  of  the  School-ship  'Mercury'  in  the  Tropical  Atlantic, 
with  a  Report  to  the  Commissioners  of  Public  Charities  and  Coi-rection 
of  the  City  of  JS'ew  York  on  the  Chemical  and  Physical  Facts  collected 
from  the  Ueep-sea  Pesearches  made  during  the  Voyage  of  the  Nautical 
School-ship  '  Mercury,'  undertaken  in  the  Tropical  Atlantic  and  Carib- 
bean Sea,  1870-71.  By  Henry  Draper,  M.D.,  Professor  of  Analytical 
Chemistry  and  Physiology  in  the  University  of  ]^ew  York.  Abstracted 
in  Nature,  vol.  v.  p.  324. 


234  THE  DEPTHS  OF  THE  SEA.  [chap.  v. 

After  sloping  gradually  to  a  depth  of"  500  fathoms 
to  the  westward  of  the  coast  of  Ireland  in  lat.  52°  N., 
the  bottom  suddenly  dips  to  1^700  fathoms  at  the 
rate  of  about  fifteen  to  nineteen  feet  in  the  100 ; 
and  from  tliis  point  to  within  about  200  miles  of 
the  coast  of  Newfoundland  Avhen  it  begins  to  shoal 
again,  there  is  a  vast  undulating  submarine  plain, 
averaging  about  2,000  fathoms  in  depth  below  the 
surface — the  '  telegraph  plateau.' 

A  valley  about  500  miles  wide,  and  with  a  mean 
depth  of  2,500  fathoms,  stretches  from  off  the  south- 
west coast  of  Ireland,  along  the  coast  of  Europe 
dipping  into  the  Bay  of  Biscay,  past  the  Strait  of 
Gibraltar,  and  along  the  west  coast  of  Africa.  Oppo- 
site the  Cape  de  Yerde  Islands  it  seems  to  merge  into 
a  slightly  deeper  trough,  which  occupies  the  axis  of 
the  South  Atlantic  and  passes  into  the  Antarctic  Sea. 
A  nearly  similar  valley  curves  round  the  coast  of 
North  America,  about  2,000  fathoms  in  depth  off 
Newfoundland  and  Labrador,  and  becoming  consider- 
ably deeper  to  the  southward ;  where  it  follows  the 
outline  of  the  coast  of  the  States  and  the  Bahamas 
and  Windward  Islands,  and  finally  joins  the  central 
trough  of  the  South  Atlantic  off  the  coast  of  Brazil, 
Avith  a  depth  of  2,500  fathoms.  A  wide  nearly  level 
elevated  tract  with  a  mean  depth  below  the  surface 
of  1,500  fathoms,  nearly  equal  in  area  to  the  con- 
tinent of  Africa,  extends  southwards  from  Iceland  as 
far  as  the  20th  parallel  of  north  latitude.  This 
plateau  culminates  at  the  parallel  of  40°  north 
latitude  in  the  volcanic  group  of  the  A9ores.  Pico, 
the  highest  point  of  the  Acores,  is  7,63  3  feet  (1,201 
fathoms)  al)ove  the  level  of  the  sea,  which  gives  from 


CHAP,  v.] 


DEEP-SEA  SOUNDING. 


235 


the  level  of  the  plateau  a  height  of  16,206  feet  (2,701 
fathoms),  a  little  more  than  the  height  of  Mont 
Blanc  above  the  sea-level. 

Accurate  soundings  are  as  yet  much  too  distant 
to  justify  anything  like  a  detailed  contour  map  of  the 
bed  of  the  Atlantic,  and  such  a  sketch  as  the  one 
here  given  can  only  be  regarded  as  a  first  rough 
draft.  Nothing,  however,  can  give  a  more  erroneous 
or  exaggerated  conception  of  its  outline  than  the 
ideal  section  in  Captain  Maury's  '  Physical  Geo- 
graphy of  the  Sea,'  although  it  is  in  a  certain  sense 
correct. 

According  to  our  present  information,  we  must 
regard  the  Atlantic  Ocean  as  covering  a  vast  region 
of  wide  shallow  valleys  and  undulating  plains,  with 
a  f^w  groups  of  volcanic  mountains,  insignificant 
both  in  height  and  extent,  when  we  consider  the 
enormous  area  of  the  ocean  bed. 


XOUSO,    KUOM   THE   HILLS   ABOVE  THORSHAVN 


CHAPTER  VI. 

DEEP-SEA   DREDGING. 

Tho  Naturalist's  Dredge. — 0.  F.  Miiller. — Ball's  Dredge. — Dredging 
at  moderate  Depths. — The  Dredge-rope. — Dredging  in  Deep 
Water. — The  *  Hempen  tangles.' — Dredging  on  board  the  *  Porcu- 
pine.'— The  Sieves. — The  Dredger's  Note-book. — The  Dredging 
Committee  of  the  British  Association. — Dredging  on  the  Coast  of 
Britain. — Dredging  abroad. — History  of  the  Progress  of  Know- 
ledge of  the  Abyssal  Fauna. 

Appendix  A. — One  of  the  Dredging  Papers  issued  by  the  British 
Association  Committee,  filled  up  by  Mr.  MacAndrew. 

Up  to  the  middle  of  last  century  the  little  that 
was  known  of  the  inhabitants  of  the  bottom  of  the 
sea  beyond  low-water  mark,  seems  to  have  been 
gathered  almost  entirely  from  the  few  objects  found 
thrown  upon  the  beach  from  time  to  time  after 
storms,  and  from  chance  captures  on  lead-lines,  and 
by  fishermen  on  their  long  lines  and  in  trawls  and 
oyster  and  clam  dredges.  Even  these  precarious 
sources  of  information  could  not  be  used  to  the 
utmost,  for  it  was  next  to  impossible  to  induce  fisher- 
men to  bring  ashore  anything  except  the  regular 
objects  of  their  industry.  Even  now  the  schoolmaster 
has  scarcely  made  way  enough  to  eradicate  old  pre- 
judices. Eishermen  are  often  so  absolutely  ignorant 
of  the  nature  of  these  extraneous  animals,    that  it 


cnAP.  VI.]  DEEP-SEA  DREDGING.  237 

is  conceivable  to  them  that  they  may  be  devils  of 
some  kind  which  may  have  the  power  in  some  occult 
way  of  influencing  them  and  the  results  of  their 
fishing.  I  believe,  however,  that  with  the  progress 
of  education  this  notion  is  dying  out  in  most  places, 
and  tliat  now  fewer  rarities  and  novelties  are  lost 
because  it  is  '  unlucky'  to  keep  them  in  the  boat. 

Tiie  naturalist's  dredge  does  not  appear  to  have 
been  systematically  used  for  investigating  the  fauna 
of  the  bottom  of  the  sea,  until  it  was  employed  by 
Otho  ^Frederick  Mtiller  in  the  researches  which 
afforded  material  for  the  publication  in  1779  of  his 
admirable  "  Descriptions  and  History  of  the  rarer  and 
less  known  Animals  of  Denmark  and  Norway."  In 
the  preface  to  the  first  volume  Mtiller  gives  a  quaint 
account  of  his  machinery  and  mode  of  working  which 
it  is  pleasant  to  read. 

The  first  paragraph  quoted  gives  a  description  of  a 
dredge  not  very  unlike  that  used  by  Ball  and  Eorbes 
(Eig.  44),  only  the  mouth  of  the  dredge  seems  to 
have  been  square,  a  modification  of  the  ordinary 
form  which  we  find  useful  for  some  purposes  still, 
but  in  most  cases  it  gives  fatal  facilities  for  '  wash- 
ing out '  in  the  process  of  hauling  in. 

"  Praecipuum  instrumentum,  quo  fundi  maris  et 
sinuum  incolas  extrahere  conabar,  erat  Sacculus  re- 
ticularis, ex  funiculis  cannabinis  concinnatus,  mar- 
gine  aperturae  alligatus  laminis  quatuor  ferreis  ora 
exteriori  acutis,  vlnam  longis,  quatuor  vncias  latis, 
et  in  quadratum  dispositis.  Angulis  laminarum  ex- 
surgebant  quatuor  bacilli  ferrei,  altera  extremitate  in 
annulum  liberum  iuncti.  Huic  annectitur  funis  du- 
centarum  et  plurium  orgyarum  longitudine.    Saccus 


238  THE  DEPTHS  OF  THE  SEA.  [chap.  vi. 

mari  immissus  pondere  ferrei  apparatus  fundum 
plerumque  petit,  interdum  diuersorum  et  contra- 
riorum  saepe  fluminum  maris  inferiorum  aduersa 
actione  *  moleque  ipsius  funis  plurium  orgyarum  in 
via  retineri,  nee  fundum  attingere  creditur." 

The  figure  of  this  first '  naturalist's  dredge  '  is  taken 
from  an  ornamental  scroll  on  the  title-page  of 
Mailer's  book. 

"Eundo  iniaeens  ope  remorum  aut  venti  modici 
trahitur,  donee  tractum  quendam  quaeuis  obuia  exci- 
piendo  confecerit.  In  cymbam  denique  retrahitur  spe 
et  labore,  at  opera  et  oleum  saepe  perditur,  nubesque 
pro  lunone  captatur,  vel  enim  totus  argil  la  fumante 
aut  limo  foetente,  aut  meris  silicibus,  aut  testaceorum 
et  coralliorum  emortuorum  quisquiliis  impletur,  vel 
saxis  praeruptis  et  latebrosis  cautibus  implicitus 
horarum  interuallo  vel  in  perpetuum  omnia  experi- 
entis  retrahendi  inuenta  frustrat ;  interdum  quidem 
vnum  et  alterum  molluscum,  helmintliicum,  aut  tes- 
taceum  minus  notum  in  dulce  laborum  lenimen 
reportat."  Muller  graphically  describes  the  difficul- 
ties which  he  encountered- in  carrying  on  his  work. 
The  paucity  of  animal  life  on  the  Scandinavian  coasts : 
the  wild  and  variable  climate,  ''  aeris  intemperies, 
marisque  in  sinubus  et  oris  maritimis  Norvegiae 
ineonstantia  adeo  praepropera  et  praepostera,  vt  aer 
calidissimus  vix  minutorum  interuallo  in  frigidum, 
tempestas  serena  in  horridam,  malacia  infida  in  aestu 
ferventem  pelagum  baud  raro  mutetur."  Still  nothing 
can  quell  the  energy  of  the  enthusiastic  old  naturalist, 
who  looks  upon  all  his  hardships  as  part  of  the  day's 
work:  "Hanc  mutationem  saepius  cum  vitae  periculo 
et    sanitatis    dispendio    expertus    sum,   nee    tamen, 


:;iAP.  VI. J 


DEEP-SEA  DREDGING. 


239 


membra  licet  fractus,  animum  demisi,  nee  ab  incepto 
desistere  potui.  .  Discant  dehinc  historiae  naturalis 
scituli,  rariora  naturae  absque  indefesso  labore  nee 
comparari,  nee  iuste  nosci."^  It  does  not-  appear, 
however,  that  Otho  Erederick  MiiUer  dredged  much 
beyond  thirty  fathoms,  and  in  his  day  the  knowledge 
of  marine  animals  was  not  sufB.ciently  advanced  to 
warrant  any  generalization  as 
to  their  bathymetrical  distri- 
bution. 

The  instrument  usually  em- 
ployed in  this  and  other 
northern  countries  for  dredg- 
ing oysters  and  clams  is  a 
light  frame  of  iron  about  five 
feet  long  by  a  foot  or  so  in 
width  at  the  mouth,  with  a 
scraper  like  a  narrow  hoe  0:1 
one  side,  and  a  suspending 
apparatus  of  thin  iron  bars 
Avhich  meet  in  an  iron  ring  for 
the  attachment  of  the  dredge 
rope  on  the  other.  Prom 
the  frame  is  suspended  a  bag- 
about  two  feet  in  depth,  of 
iron  chain  netting,  or  of  wide-meshed  hempen  cord 
netting,  or  of  a  mixture  of  both.  Naturalist  dredgers 
at  first  used  the  oyster  dredge,  and  all  the  different 
dredges  now  in  use  are  modifications  of  it  in  one 
direction  or  in  another ;  for  in  its  simplicity  it  is  not 

^  Zoologia  Danica.  Sev  Aiiimalivm  Dauiae  et  K'orvegiae  rariorum 
ac  minvs  notorvm  Descriptiones  et  Historia.  Avctore  Othone  Friderico 
Mliller.     Havniae,  1788. 


Fig.  44.— Otlio  Frederick  Mlillei" 
Dredge.    a.d.  1750. 


240 


THE  DEPTHS  OF  THE  SEA. 


[chap.   VI. 


suitable  for  scientific  purposes.  The  oyster  dredge 
has  a  scraper  only  on  one  side.  In  the  skilled  hands 
of  the  fishermen  this  is  no  disadvantage,  for  it  is 
always  sent  down  in  such  a  way  that  it  falls  face 
foremost,  but   philosophers   using  it  in   deep  water 

very  generally  found  that 
whether  from  clumsiness 
or  from  want  of  sufficient 
practice,  they  had  got  the 
dredge  down  on  its  back, 
and  of  course  it  came 
up  empty.  Again,  oyster 
dredgers  are  only  allowed 
to  take  oysters  of  a  certain 
size,  and  the  meshing  of 
the  commercial  dredge  is 
so  contrived  as  to  alloAV 
all  bodies  under  a  certain 
considerable  size  to  pass 
through.  This  defeats  the 
object  of  the  naturalist; 
for  some  of  the  prizes 
to  which  he  attaches  the 
highest  value  are  mites  of 
things  scarcely  visible  to 
the  unaided  eye. 

The  remedy  for  these  de- 
fects is  to  have  a  scraper 
on  each  side,  with  the  arms  attached  in  such  a  way 
that  one  or  other  of  the  scrapers  must  reach  the 
ground  in  whatever  position  the  dredge  may  fall ;  and 
to  have  the  bag  deeper  in  proportion  to  the  size  of 
the  frame,  and  of  a  material  which  is  only  sufficiently 


Fig.  45.—'  Ball's  Dredge. 


CHAP.  VI.]  DEEP-SEA  DREDGING.  241 

open  to  allow  the  water  to  pass  freely  through,  with 
the  openings  so  distributed  as  to  leave  a  part  of  the 
bag  close  enough  to  bring  up  the  finest  mud. 

The  late  Dr.  Robert  Ball  of  Dublin  devised  the 
modification  which  has  since  been  used  almost  uni- 
versally by  naturalists  in  this  country  and  abroad 
under  the  name  of  'Ball's  Dredge'  (Fig.  45).  The 
dredges  on  this  pattern  used  in  Britain  for  ten 
years  after  their  first  introduction  about  the  year 
1838,  were  usually  small  and  rather  heavy — not 
more  than  from  twelve  to  fifteen  inches  in  length 
by  four  or  four  and  a  half  inches  in  width  at  the 
mouth.  There  w^ere  two  scrapers  the  length  of  the 
dredge-frame  and  an  inch  and  a  half  or  two  inches 
wide,  set  at  an  angle  of  about  110°  to  the  plane 
of  the  dredge's  mouth,  so  that  when  the  dredge 
was  gently  hauled  along  it  took  hold  of  the  ground 
and  secured  anything  loose  on  its  surface.  I  have 
seen  Dr.  Ball  scatter  pence  on  the  drawing-room 
floor  and  pick  them  up  quite  dexterously  with 
the  dredge  drawn  along  in  the  ordinary  dredging 
position. 

Latterly  we  have  used  Ball's  dredges  of  consider- 
ably larger  size.  Perhaps  the  most  convenient  form 
and  size  for  dredging  from  a  row-boat  or  a  yawl  at 
depths  under  a  hundred  fathoms  is  that  represented 
by  Pig.  45.  The  frame  is  eighteen  inches  long,  and 
its  width  is  five  inches.  The  scrapers  are  three 
inches  wide,  and  they  are  so  set  that  the  distance 
across  between  their  scraping  edges  is  seven  inches 
and  a  half.  The  ends  of  the  frame  connecting  the 
scrapers  are  round  bars  of  iron  five-eighths  of  an 
inch  in  diameter,  and  from  these  two  curved  arms  of 


242  THE  DEPTHS  OF  THE  SEA.  [chap.  vi. 

round  iron  of  the  same  thickness,  dividing  heneath 
into  two  branches  which  are  attached  to  the  ends  of 
the  cross-bars  by  eyes  allowing  the  arms  to  fold  down 
over  the  dredge-mouth,  meet  in  two  lieavy  eyes  at  a 
point  eighteen  inches  above  the  centre  of  the  frame. 
The  total  weight  of  the  dredge-frame  and  arms  is 
twenty  pounds.  It  ought  to  be  of  the  best  Low- 
moor  on  Swedish  wrought-iron.  I  have  seen  a  stout 
dredge-frame  of  Lowmoor  iron  twisted  like  a  bit 
of  wax  in  extricating  it  from  a  jam  between  two 
stones,  and,  singularly  enough,  the  dredge  which 
came  up  in  that  condition  contained  the  unique 
example  of  an  echinoderm  never  found  before  or 
since.  SI 

The  thick  inner  edges  of  the  scrapers  are  perforated"^" 
by  round  holes  at  distances  of  about  an  inch,  and 
through  these,  strong  iron  rings  about  an  inch  in 
diameter  are  passed,  and  two  or  three  like  rings  run 
on  the  short  rods  which  form  the  ends  of  the  dredge- 
frame.  A  light  iron  rod  bent  to  the  form  of  the 
dredge  opening  usually  runs  through  these  rings,  and 
to  this  rod  and  to  the  I'ings  the  mouth  of  the  dredge- 
bag  is  securely  attached  by  stout  cord  or  strong 
copper  wire.  j 

In  the  dredge  now  before  me,  which  has  worked  ^ 
well  and  seen  good  service,  the  bag  is  two  feet  in 
depth,  and  is  of  hand-made  net  of  very  strong  twine, 
the  meshes  half  an  inch  to  the  side.  So  open 
a  network  would  let  many  of  the  smaller  things 
through,  and  to  avoid  this  the  bottom  of  the  bag,  to 
the  height  of  about  nine  inches,  is  lined  with  '  bread- 
bag,'  a  light  open  kind  of  canvas. 

Manv  other  materials  have  been  used  for  dredo-e- 


CHAP.  VI.]  DEEP-SEA  DREDGING.  243 

bags.  Raw  buffalo-  and  cow-hides  are  very  strong, 
but  they  are  apt  to  become  offensive.  When  these 
are  used  it  is  necessary  to  punch  holes  here  and  there 
to  let  the  water  through  or  to  leave  the  seams  which 
are  sewed  with  thongs  a  little  open.  Another  bag 
which  I  have  used  frequently  is  made  of  sail-cloth, 
with  a  window  of  strong  brass  wire  gauze  let  in  on 
either  side.  Nothing,  however,  seems  to  me  so  good 
as  strong  cord  netting.  The  water  passes  easily 
through  and  carries  with  it  a  large  part  of  the  fine 
mud,  while  enough  mud  is  retained  by  the  bread- 
bag  lining  in  the  bottom  to  give  a  fair  sample  of  its 
contents.  It  may  be  said  that  many  small  valuable 
objects  may  be  washed  through  the  meshes  of  the 
upper  part  of  the  dredge  along  with  the  mud,  and 
thus  lost ;  but,  on  the  other  hand,  if  the  bag  be  very 
close  it  is  apt  to  get  filled  up  with  mud .  at  once,  and 
to  collect  nothing  more. 

It  is  always  well  when  dredging,  at  whatever 
depth,  to  ascertain  the  aj)proximate  depth  with  the 
lead  before  casting  the  dredge ;  and  the  lead  ought 
always  to  be  accompanied  by  a  protected  thermome- 
ter, for  the  subsequent  haul  of  the  dredge  will  gain 
greatly  in  value  as  an  observation  in  geographical 
distribution  if  it  be  accompanied  by  an  accurate  note 
of  the  bottom  temperature.  For  depths  under  100 
fathoms  the  amount  of  rope  paid  out  should  be  at 
least  double  the  depth.  Under  thirty  fathoms,  where 
one  generally  works  more  rapidly,  it  should  be  more 
nearly  three  times.  This  gives  a  good  deal  of  sla<jk 
before  the  dredge  if  the  boat  be  moving  very  slowly, 
and  keeps  the  lip  of  the  dredge  well  down ;  and  if  the 
boat  be  moving  too  quickly  through  the  water,  by 

11  2 


244  THE  DEPTHS  OF  THE  SEA.  [chap.  vi. 

far  the  most  common  error  in  amateur  dredging, 
Irom  the  low  angle  at  which  the  line  is  lying  in  the 
water  the  dredge  has  its  hest  chance  of  getting  an 
occasional  scrape.  It  is  bad  economy  to  use  too 
light  a  rope.  I'or  a  dredge  such  as  that  described, 
and  for  work  round  the  coasts  of  Europe  at  depths 
attainable  from  a  row-boat  or  yawl,  I  would  recom- 
mend bolt-rope  of  the  best  Russian  hemp,  not  less 
than  one  and  a  half  inch  in  circumference,  which 
should  contain  from  eighteen  to  twenty  yarns 
in  three  strands.  Each  yarn  should  bear  nearly  a 
hundredweight,  so  that  the  breaking  strain  of  such  a 
rope  ought  to  be  upwards  of  a  ton.  Of  course  it  is 
never  voluntarily  exposed  to  such  a  strain,  but  in 
shallow  water  the  dredge  is  often  caught  among 
rocks  or  coral,  and  the  rope  ought  to  be  strong 
enough  in  such  a  case  to  bring  up  the  boat,  even  if 
there  were  some  little  way  on. 

Dredging  in  sand  or  mud,  the  dredge-rope  may 
simply  be  passed  through  the  double  eye  formed  by 
the  extremities  of  the  two  arms  of  the  dredge ;  but  in 
rocky  or  unknown  ground  it  is  better  to  fasten  the 
rope  to  the  eye  of  one  of  the  arms  only,  and  to  tie  the 
two  eyes  together  with  about  three  or  four  turns  of 
rope  yarn.  This  breaks  much  more  readily  than  the 
dredge  rope,  so  that  if  the  dredge  get  caught  it  is 
the  first  thing  to  give  way  under  a  strain,  and  in 
doing  so  it  very  often  so  alters  the  position  and  form 
of  the  dredge  as  to  allow  of  its  extrication. 

The  dredge  is  slipped  gently  over  the  side,  either 
from  the  bow  or  from  the  stern — in  a  small  boat 
more  usually  the  latter — wliile  there  is  a  little  way 
on,   and   the   direction   which   the   rope  takes  indi- 


CHAP.  VI.]  DEEP-SEA  DREDGING.  '^45 

cates  roughly  whether  the  dredge  is  going  down 
properly.  When  it  reaches  the  ground  and  hegins 
to  scrape,  an  experienced  hand  upon  the  rope  can 
usually  at  once  detect  a  tremor  given  to  the  dredge 
by  the  scraper  passing  over  the  irregularities  of  the 
bottom.  The  due  amount  of  rope  is  then  paid  out, 
and  the  rope  hitched  to  a  bench  or  rollock-pin. 

When  there  is  anything  of  a  current,  from  Avhat- 
ever  cause,  it  is  usually  convenient  to  attach  a  weight 
varying  from  fourteen  pounds  to  lialf  a  hundred- 
weight, to  the  rope  three  or  four  fathoms  in  front  of 
the  dredge.  This  prevents  in  some  degree  the  lift- 
ing of  the  mouth  of  the  dredge.  If  the  weight  be 
attached  nearer  the  dredge,  it  is  apt  to  injure  delicate 
objects  passing  in. 

The  boat  should  move  very  slowly,  probably  not 
faster  than  a  mile  an  hour.  In  still  water,  or  with 
a  very  slight  current,  the  dredge  of  course  anchors 
the  boat,  and  oars  or  sails  are  necessary;  but  if 
the  boat  be  moving  at  all  it  is  all  that  is  required. 
I  like  best  to  dredge  with  a  close-reefed  sail  before  a 
light  wind,  with  weights,  against  a  very  slight  tide 
or  current ;  but  these  are  conditions  which  cannot 
always  be  commanded.  The  dredge  may  remain 
down  from  a  quarter  of  an  hour  to  twenty  minutes, 
by  which  time,  if  things  go  well,  it  ought  to  be 
fairly  filled. 

In  dredging  from  a  small  boat  the  simplest  plan  is 
for  two  or  three  men  to  haul  in  hand  over  hand  and 
coil  in  the  bottom  of  the  boat.  For  a  large  yawl 
or  yacht,  and  for  depths  beyond  fifty  fathoms,  a 
winch  is  a  great  assistance.  The  rope  takes  a  couple 
of  turns  round  the  winch,  which  is  worked  by  two 


246  THE  DEPTHS  OF  THE  SEA.  [chap.  vi. 

men,  while  a  third  takes  it  from  the  winch  and 
coils  it. 

Dredging  in  deep  water— that  is,  at  depths  beyond 
200  fathoms — is  a  matter  of  some  difTiculty,  and  can 
scarcely  be  compassed  with  the  ordinary  machinery 
at  the  disposal  of  amateurs.  Deep-sea  dredging  can 
no  doubt  be  carried  on  from  a  good-sized  steam  yacht, 
but  the  appliances  are  so  numerous  and  so  bulky, 
and  the  work  is  so  really  hard,  that  it  is  scarcely 
compatible  with  pleasure-seeking. 

I  do  not  know  that  much  improvement  can  be 
made  upon  the  apparatus  and  method  employed  in 
the  '  Porcupine '  in  1869  and  1870.  I  will  therefore 
describe  her  dredging  gear  and  the  dredging  opera- 
tion carried  on  from  her  at  the  greatest  depths  in 
the  Bay  of  Biscay,  that  which  tested  our  resources 
most  fully,  somewhat  in  detail. 

The  '  Porcupine '  is  a  382-ton  gun-boat,  fitted  up 
for  the  surveying  service,  in  which  she  has  been  em- 
ployed for  some  years  past  among  the  Hebrides,  and 
latterly  on  the  east  coast  of  England.  She  was 
assigned  for  our  special  work  in  1869,  with  all  her 
ordinary  surveying  fittings;  and  certain  very  im- 
portant additions  were  made;  among  others  the 
double-cylinder  donkey  engine,  which  worked  up 
to  about  twelve  horse-power,  with  surging  drums 
of  different  sizes,  large  drums  for  bringing  up  light 
weights  rapidly,  and  smaller  drums  for  heavy  work. 
This  engine  was  set  up  amidships,  so  that  lines  could 
be  led  to  the  drums  either  from  fore  or  aft.  The 
donkey-engine  proved  a  most  serviceable  little 
machine.  We  almost  always  used  the  large  drum, 
both  in  dredging  and  sounding ;  and  except  on  one 


CHAP.  VI.]  DEEP-SEA  DREDGING.  247 

or  two  occasions  when  an  enormous  load,  once 
nearly  a  ton,  came  up  in  the  dredge-bag-,  it  de- 
livered the  rope  steadily,  at  a  uniform  rate  of  more 
than  a  foot  per  second,  for  the  whole  summer. 

A  powerful  derrick  projected  over  the  port  bow. 
A  large  block  was  suspended  at  the  end  of  the 
derrick  by  a  rope  which,  as  in  the  case  of  the  sound- 
ing-line, was  not  directly  attached  to  the  spar  but 
passed  through  an  eye,  and  was  attached  to  a  '  bitt ' 
on  deck.  On  a  bight  of  this  rope  was  lashed  a 
powerful  accumulator,  the  machine  already  described 
(p.  222)  as  of  so  much  use  in  the  management  of 
the  sounding-line.  In  dredging  from  a  large  vessel 
the  '  accumulator '  is  invaluable.  Prom  the  great 
strength  of  the  springs  the  dredge  is  usually  drawn 
along  without  stretching  them  to  any  great  degree  ; 
they  become  tense  and  taut,  and  yield,  with  a  kind 
of  slight  pulsation,  to  the  rise  and  fall  of  the  vessel. 
Whenever  they  run  out  it  is  a  sure  indication  that 
either  the  dredge  has  caught  or  the  weight  in  it  is 
becoming  too  great,  and  that  the  dredge  rope  ought 
to  be  relieved  by  a  turn  of  the  paddle-wheel  or  screw. 
Care  should  be  taken  not  to  have  the  bight  of  the 
rope  to  which  the  accumulator  is  attached  more 
than  about  twice  the  length  of  the  unstretched 
springs.  Springs  in  good  order  ought  to  stretch  to 
much  more  than  double  their  length ;  but  it  is  unsafe 
to  try  them  too  far,  as  a  lash  from  one,  if  it  were  to 
give  way,  would  be  most  serious.  When  a  great 
strain  comes  upon  the  rope,  it  acts  first  upon  the 
accumulator,  pulling  down  the  block  and  stretching 
the  elastic  bands ;  and  a  graduated  scale  on  the  der- 
rick, against  w^hich  the  accumulator  i)lays,  gives  in 


248 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VI. 


Fig.  46.— The  Stern  Derrick  of  the  'Porcupine/  showing  tl)e  '  accuuiuiator  '  tne  ureuge,  and 
the  mode  of  stowing  the  rope. 


CHAP.  VI.]  DEEP-SEA  DREDGING.  249 

cwts.  an  approximation  at  all  events   to  the  strain 
on  the  rope. 

A  second  derrick,  nearly  equally  strong,  was  rigged 
over  the  stern,  and  we  dredged  sometimes  from  one 
and  sometimes  from  the  other.  The  stern  derrick  was, 
however,  principally  used  for  sounding ;  the  letting- 
go  board,  &c.,  being  fitted  up  in  connection  with  it. 
We  had  an  excellent  arrangement  for  stowing  the 
dredge-rope  in  the  '  Porcupine ;'  an  arrangement 
which  made  its  manipulation  singularly  easy,  not- 
withstanding its  great  weight — about  5,500  lbs.  A  row 
of  about  twenty  great  iron  pins,  about  two  and  a  half 
feet  in  length,  projected  over  one  side  of  the  quarter- 
deck, rising  obliquely  from  the  top  of  the  bulwark. 
Each  of  these  held  a  coil  of  from  two  to  three  hun- 
dred fathoms,  and  the  rope  was  coiled  continuously 
along  the  whole  row  (Fig.  46).  When  the  dredge 
was  going  down,  the  rope  was  taken  rapidly  by  the 
men  from  these  pins— 'Aunt  Sallies'  we  called  them, 
from  their  ending  over  the  deck  in  smooth  white 
balls — in  succession,  beginning  with  the  one  nearest 
the  dredging  derrick ;  and  in  hauling  up,  a  relay  of 
men  carried  the  rope  along  from  the  surging  drum 
of  the  donkey-engine  and  laid  it  in  coils  on  the  pins 
in  inverse  order.  Thus,  in  letting  go,  the  rope 
passed  to  the  block  of  the  derrick  directly  from  the 
'  Aunt  Sallies ; '  in  hauling  up,  it  passed  from  the 
1)lock  to  the  surging  drum  of  the  donkey-engine, 
from  which  it  was  taken  by  the  men  and  coiled  on 
the  '  Aunt  Sallies.' 

The  length  of  the  dredge-rope  was  3,000  fathoms, 
nearly  three  and  a  half  statute  miles.  Of  this,  2,000 
fathoms    were    'hawser-laid,'    of    the    best    Russian 


250  THE  DEPTHS  OF  THE  SEA.  •         [chap.  vi. 

hemp,  2^  inches  in  circumference,  with  a  breaking 
strain  of  2\  tons.  The  1,000  fathoms  next  the 
dredge  were  *  hawser-laid,'  2  inches  in  circumference. 
A  Russian  hemp  rope  appears  to  be  the  most  suit- 
able. A  manilla  rope  is  considerably  stronger  for 
a  steady  pull,  but  the  fibre  is  more  brittle  and  liable 
to  go  at  a  '  kink.'  I  have  never  seen  a  wire-rope  used, 
but  I  should  think  it  would  be  liable  to  the  same 
objection.  The  'Challenger'  is  to  be  supplied  with 
'  whale-line '  for  her  great  expedition.  The  frame  of 
one  of  the  dredges  which  we  used  in  the  Bay  of 
Biscay  is  represented  at  Pigs.  47  and  48.   The  length  of 


^^^ 


<- G 

Fig.  47.— The  Eijd  of  the  Dredge  frame. 


the  dredge-frame  is  4  ft.  6  in.,  and  it  is  6  inches  wide 
at  the  throat  or  narrowest  part.  The  dredge  used  in 
the  deepest  haul  was  somewhat  different.  About 
half  of  each  arm  next  the  eye  to  which  the  rope  was 
attached,  was  of  heavy  chain.  I  doubt  greatly,  how- 
ever, if  this  is  an  advantage.  The  chain  drags  along 
in  front  of  the  dredge,  and  may  possibly  obstruct 
the  entrance  of  objects  and  injure  them  more  than  a 
pair  of  rigid  arms  would  do.  On  one  side  the  chain 
was  attached  to  the  arm  of  the  dredge  by  a  stop  of 
five  turns  of  spun-yarn,  so  that  in  case  of  the  dredge 


CHAP.  VI.] 


BEEP-SEA  DREDGING. 


251 


becoming  entangled  or  wedged  among  rocks  or 
stones,  a  strain  less  than  sufficient  to  break  the 
dredge  rope  would  break  the  stop,  alter  the  position 
of  the  dredge,  and  probably  enable  it  to  free  itself ; 


Fio.  48  — Dredge-frame  showing  the  mode  of  attachment  of  the  Bag.    a.  Spunyam  Stop^ 

and  in  case  of  its  taking  in  a  greater  load  of  mud 
than  the  rope  could  bring  up,  the  stop  would  like- 
wise give  way  and  allow  the  dredge  to  fall  into  such 
a  position  that  a  large  part  of  its  contents  would  slip 


252 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VI. 


out.  The  weight  of  the  frame  of  this  dredge,  the 
largest  we  ever  used,  was  225  lbs. ;  it  was  forged  by 
Messrs.  Harland  and  Wolff  of  Eelfast  of  the  best 
Lowmoor  iron.  The  dredge-bag  was  double — the 
outer  of  strong  twine  netting,  the  inner  of  bread- 
bag.  Three  sinkers — one  of  1  cwt., 
the  other  two  of  56  lbs.  each — were 
attached  to  the  dredge- rope  at  500 
fathoms  from  the  dredge. 

The  operation  of  sounding  at  a 
depth  of  2,435  fathoms  in  the  Bay 
of  Biscay  on  the  22nd  of  July,  1869, 
has  already  been  described  in  detail. 
When  the  depth  had  been  accurately 
ascertained,  about  4.45  p.m.  the 
dredge  was  let  go,  the  vessel  drift- 
ing slowly  before  a  moderate  breeze 
(force  =  4)  from  the  N.W.  The  3,000 
fathoms  of  rope  were  all  out  at  5.50 
P.M.  The  diagram  (Fig.  50)  will 
give  an  idea  of  the  various  relative 
positions  of  the  dredge  and  the  vessel 
according  to  the  plan  of  dredging 
adopted  by  Captain  Calver,  which 
worked  admirably,  and  which  ap- 
pears, in  fact,  to  be  the  only  mode 
wliich  would  answer  for  great  depths. 
A  represents  the  position  of  the  vessel  when  the 
dredge  is  let  go,  and  the  dotted  line  A  b  the  line  of 
descent  of  the  dredge,  rendered  oblique  by  the  ten- 
sion of  the  rope.  While  the  dredge  is. going  down 
the  vessel  drifts  gradually  to  leeward ;  and  when 
the  whole  (say)  3,000  fathoms  of  rope  are  out,  c,  w, 


Pig.  49.— The  End  of  the 
Dredge-frame,  showing 
the  mode  of  attachment 
of  the  Bag. 


CHAP.  VI.]  DEEP-SEA  DREDGING.  253 

and  D  might  represent  respectively  the  relative  jjosi- 


FiG.  50.— Diagram  of  the  relative  position  of  the  Vessel,  the  Weights,  and  the  Dredge,  in 
dredging  in  deep  water. 


tions  of  the  vessel,  the  weight  attached  500  fathoms 


254  THE  DEPTHS  OF  THE  SEJ.  [chai'.  vi. 

from  the  dredge,  and  the  dred^  itself.  The  vessel  now 
steams  slowly  to  windward,  occupying  successively 
the  positions  E,  F,  G,  and  H.  The  weight,  to  which 
the  water  oflFers  but  little  resistance,  sioks  from 
w  to  w ,  and  the  dredge  and  Lag  more  sloAvly  from 
D  to  B.  The  vessel  is  now  allowed  to  drift  back 
before  the  wind  from  h  towards  c.  The  tension  of 
the  motion  of  the  vessel,  instead  of  acting  immedi- 
ately on  the  dredge,  now  drags  forward  tlie  weight 
Tv',  so  that  the  dredging  is  carried  on  from  the 
weight  and  not  directly  from  the  vessel  The 
dredge  is  thus  quietly  pnlled  along  ^vith  its  lip 
scraping  the  bottom  in  the  attitude  which  it 
assumes  from  the  centre  of  weight  of  its  iron  frame 
and  arms.  If,  on  the  other  hand,  the  weights 
were  hung  close  to  the  dredge,  and  the  dredge  were 
dragged  directly  from  the  vessel,  owing  to  the  great 
weight  and  spring  of  the  rope  the  arms  would  be 
continually  lifted  up  and  the  lip  of  the  dredge  pre- 
vented from  scraping.  In  very  deep  dredging  this 
operation  of  steaming  up  to  windward  until  the 
dredge-rope  is  nearly  perpendicular,  after  drifting 
for  half  an  hour  or  so  to  leeward,  is  usually 
repeated  three  or  four  times. 

At  8.50  P.M.  we  began  to  haul  in,  and  the  *  Aunt 
Sallies'  to  fill  agaio.  The  donkey-engine  delivered 
the  rope  at  the  rate  of  rather  more  than  a  foot  per 
second,  without  a  single  check.  A  few  minutes 
before  1  A.>t,  the  weights  appeared,  and  a  little  after 
one  in  the  morning,  eight  hours  after  it  was  cast 
over,  the  dredge  was  safely  hauled  on  deck,  having 
in  the  internal  accomplished  a  journey  of  upwards 
of  eight  statute  mile^i.     The  dredge  contained  \\  cwt. 


CHAP.  vi.J  DEEP-SEA  DREDGING.  255 

of  very  characteristic  pale  grey  Atlantic  ooze.     The 
total  weight  brought  up  by  the  engine  was — 

2,000  fathoms,  2|-iQch  rope 4,000  lbs. 

1,000  fathoms,  2-mch  rope 1,500    „ 

5,500  lbs. 

Weight  of  rope  reduced  to  one-fourth  in  water  =  1,375  lbs. 

Dredge  and  bag 275    „ 

Ooze  brought  up 168    „ 

Weight  attached ,        224    „ 

2,042  Ihp. 

Much  more  experience  will  yet  be  necessary  before 
we  can  assure  ourselves  that  we  have  devised  the 
dredge  of  the  best  form  and  weight  for  work  in  the 
deep  sea.  I  rather  think  that  the  dredges,  150  to 
225  lbs. J  which  we  have  been  in  the  habit  of  using, 
are  too  hea^'y.  In  many  instances  we  have  had 
evidence  that  the  dredge,  instead  of  falling  gently 
upon  the  surface  and  then  gliding  along  and  gather- 
ing the  loose  things  in  its  path,  has  fallen  upon  its 
mouth  and  dug  into  the  tenacious  mud,  thereby 
cloggiug  itself,  so  as  to  admit  but  little  more.  I 
mean  to  try  the  experiment  of  heavier  weights  and 
lighter  dredge-frames  in  the  '  Challenger,'  and  I 
believe  it  will  be  an  improvement. 

In  many  of  our  dredgings  at  all  depths  we  found 
that,  while  few  objects  of  interest  were  brought  up 
within  the  dredge,  many  echinoderms,  corals,  and 
-pouges  came  to  the  surface  sticking  to  the  outside 
of  the  di-edge-bag,  and  even  to  the  first  few  fatlioms 
of  the  dredge-rope. 

This     suggested    many    exi)edients,     and    finally 


256  THE  DEPTHS  OF  THE  SEA.  [(jhap.  vi; 

Captain  Calv^er  sent  down  half-a-dozen  of  the  'swabs' 
used  for  washing  the  decks  attached  to  the  dredge. 
The  rosLilt  was  marvellous.  The  tangled  hemp 
brought  up  everything  rough  and  moveable  which 
came  in  its  way,  and  swept  the  bottom  as  it  might 
have  swept  the  deck.  Captain  Calver's  invention  ini- 
tiated a  new  era  in  deep-sea  dredging.  After  various 
experiments  we  came  to  the  conclusion  that  the 
best  plan  was  to  attach  a  long  iron  transverse  bar 
to  the  bottom  of  the  dredge-bag,  and  to  fasten  large 
bunches  of  teazed-out  hemp  to  the  free  ends  of  the 
bar  (Fig.  51).  We  now  regard  the  '  hempen  tangles  ' 
as  an  essential  adjunct  to  the  dredge  nearly  as 
important  as  the  dredge  itself,  and  usually  much 
more  conspicuous  in  its  results.  Sometimes,  when 
the  ground  is  too  rough  for  ordinary  dredging,  we 
use  the  tangles  alone.  There  is  some  danger,  how- 
ever, in  their  use.  The  dredge  employed  under  the 
most  favourable  circumstances  may  be  supposed  or 
hoped  to  pass  over  the  surface  of  the  floor  of  the 
sea  for  a  certain  distance,  picking  up  tli^e  objects  in 
its  path  which  are  perfectly  free,  and  small  enough 
to  enter  the  dredge  mouth.  If  they  chance  to  be 
attached  in  any  way,  the  dredge  rides  over  them. 
.  If  they  exceed  in  the  least  the  width  of  the  dredge- 
opening,  at  the  particular  angle  at  which  the  dredge 
may  present  itself  at  the  moment,  they  are  shoved 
aside  and  lost. 

The  Mollusca  have  by  far  the  best  chance  of  being 
fully  represented  in  investigations  carried  on  by  the 
dredge  alone.  Their  shells  are  comparatively  sm.all 
solid  bodies  mixed  with  the  stones  on  the  bottom, 
and  they  enter  the  dredge  along  with  these.     Echino- 


"CHAP.  VI.] 


DEEP-SEA  DREDGING. 


25 


derms,  corals,  and  sponges,  on  the  contrary,  are  bulky 
objects,  and  are  frequently  partially  buried  in  the 


Fio.  51. — Dredge  with  'hempen  tangles  ' 


mud   or  more  or  less  firmly  attached,   so   that  the 
dredge  generally  misses  them.     Witli  the  tangles  it 

s 


258  THE  DEPTHS  OF  THE  SEA.  [chap.  vi. 

is  the  reverse.  The  smooth  heavy  shells  are  rarely 
hrought  up,  while  frequently  the  tangles  loaded  with 
the  spiny  spheres  of  Cldarls,  great  white-hearded 
Holteniw,  glistening  coils  of  Hyalonema,  relieved  hy 
the  crimson  stars  of  Astropecten  and  Brisinga,  pre- 
sent as  remarkable  an  appearance  as  can  well  be 
imagined.  On  one  occasion,  to  which  I  have  already 
referred,  I  am  sure  not  fewer  than  20,000  examples 
of  Echinus  norvegicus  came  up  on  the  tangles  at 
one  haul.  They  were  warped  through  and  through 
the  hempen  fibres,  and  actually  filled  the  tangles 
so  that  we  could  not  get  them  out,  and  they  hung 
for  days  round  the  bulwarks  like  nets  of  pickling 
onions  in  a  greengrocer's  shop.  The  use  of  the 
tangles,  which  seem  so  singularly  well  adapted  to 
their  capture,  gives  therefore  a  totally  unfair  advan- 
tage to  the  radiate  groups  and  the  sponges,  and  this 
must  always  be  taken  into  account  in  estimating 
their  proportion  in  the  fauna  of  a  particular  area. 

The  tangles  certainly  make  a  sad  mess  of  the 
specimens ;  and  the  first  feeling  is  one  of  woe,  as  we 
undertake  the  almost  hopeless  task  of  clipping  out 
with  a  pair  of  short  nail-scissors  the  mangled 
remains  of  sea-pens,  the  legs  of  rare  crabs,  and 
the  dismembered  disks  and  separated  arms  of  delicate 
crinoids  and  ophiurids.  We  must  console  ourselves 
with  the  comparatively  few  things  which  come  up 
entire,  sticking  to  the  outer  fibres ;  and  with  the  re- 
flection that  had  we  not  used  this  somewhat  ruthless 
means  of  capture  the  mutilated  specimens  would  have 
remained  unknown  to  us  at  the  bottom  of  the  sea. 

The  dredge  comes  up  variously  freighted  according 
to  the   locality.      Usually,  if  dexterously  managed, 


CHAP.  VI.]  DEEP-SEA  DREDOINQ.  259 

the  bag  is  about  half  full.  If,  from  a  great  depth, 
beyond  the  reach  of  currents,  where  there  is  only  so 
slow  a  movement  of  the  mass  of  water  that  the  finest 
sediment  is  not  carried  away,  it  contains  usually 
fine  calcareous  or  aluminous  mud  alone,  with  the 
animals  forming  the  fauna  of  the  locality  distributed 
through  it.  In  shallower  water  we  may  have  sand 
or  gravel,  or  stones  of  various  sizes  mixed  with  mud 
and  sand. 

The  next  step  is  to  examine  the  contents  of  the 
dredge  carefully,  and  to  store  the  objects  of  search  for 
future  use.  The  dredge  is  hauled  on  deck,  and  there 
are  two  ways  of  emptying  it.  We  may  either  turn  it 
up  and  pour  out  its  contents  by  the  mouth,  or  we 
may  have  a  contrivance  by  which  the  bottom  of  the 
bag  may  be  made  to  unlace.  The  first  plan  is  the 
simplest  and  the  one  most  usually  adopted.  The 
second  has  the  advantage  of  letting  the  mass  out 
more  smoothly  and  easily,  but  the  lacing  introduces 
rather  a  damaging  complication,  as  it  is  apt  to 
loosen  or  give  way.  In  a  regularly  organized  dredg- 
ing expedition,  a  frame  is  often  arranged  with  a 
ledge  round  it  to  receive  the  contents  of  the  dredge, 
but  it  does  very  well  to  capsize  it  on  an  old  piece  of 
tarpauling.  Any  objects  visible  on  the  surface  of 
the  heap  are  now  carefully  removed  and  placed  for 
identification  in  jars  or  tubs  of  sea- water,  of  which 
there  should  be  a  number  standing  ready.  The 
heap  should  not  be  much  disturbed,  for  the  delicate 
objects  contained  in  it  have  already  been  unavoid- 
ably subjected  to  a  good  deal  of  rough  usage,  and 
the  less  friction  among  the  stones  the  better. 

Close  to  the  place  where  the   dredge  is  emptied 

s  2 


260 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VI. 


there  ought  to  be  one  or  two  tubs  about  two  feet 
in  diameter  and  twenty  inches  deep,  and  each  tub 
should  be  provided  with  a  set  of  sieves  so  arranged 
that  the  lowest  sieve  fits  freely  within  the  bottom 
of  the  tub,  and  the  three  succeeding  sieves  fit  freely 
within  one  another  (Pig.  52).  Each  sieve  is  pro- 
vided with  a  pair  of  iron  handles  through  which 
the  hand  can  pass  easily,  and  the  handles  of  the 
largest  sieve  are  made  long,  so  that  the  w^hole  nest 
can  be  lifted  without  stooping  and  putting  the  arms 


Fig.  52.— Set  of  Dredging  Sieves. 

into  the  water.  The  upper  smallest  sieve  is  usually 
deeper  than  the  others ;  it  is  made  of  a  strong  open 
net  of  brass  wire,  the  meshes  a  half  inch  to  a  side. 
The  second  sieve  is  a  good  deal  finer,  the  meshes 
a  quarter  inch  to  a  side.  The  third  is  finer  still, 
and  the  fourth  so  close  as  only  to  allow  the  passage 
of  mud  or  fine  sand.  The  sieves  are  put  into  the 
tub,  and  the  tub  filled  up  to  the  middle  of  the  top 
sieve  with  sea-water.  The  top  sieve  is  then  half 
filled  with  the  contents  of  the  dredge,  and  the  set 
of  sieves   are   gently   moved   up   and   down   in   the 


CHAP.  VI.]  DEEP-SEA  DREDGING.  2G1 

water.  It  is  of  great  importance  not  to  give  any 
rotatory  motion  to  the  sieves  in  this  part  of  the 
process,  for  such  is  very  ruinous  to  fragile  organisms. 
The  sieves  should  be  gently  churned  up  and  down, 
whether  singly  or  together.  The  result,  of  course,  is 
that  the  rougher  stones  and  gravel  and  the  larger 
organisms  are  washed  and  retained  in  the  upper 
sieve.  The  fine  mud  or  sand  passes  through  the 
whole  of  the  sieves  and  subsides  into  the  bottom  of 
the  tub,  while  the  three  remaining  sieves  contain,  in 
graduated  series,  the  objects  of  intermediate  size. 
The  sieves  are  examined  carefully  in  succession,  and 
the  organisms  which  they  contain  gently  removed 
with  a  pair  of  brass  or  bone  forceps  into  the  jars 
of  sea-water,  or  placed  at  once  in  bottles  of  weak 
spirit  of  wine. 

The  scientific  value  of  a  dredging  operation  de- 
pends mainly  upon  two  things, — the  care  with  which 
the  objects  procured  are  preserved  and  labelled  for 
future  identification  and  reference,  and  the  accuracy 
with  which  all  the  circumstances  of  the  dredging, 
position,  depth,  nature  of  ground,  bottom  tempera- 
ture, date,  &c.,  are  recorded.  With  regard  to  the 
preservation  of  the  animals,  I  cannot  here  go  into 
detail.  There  are  many  ways  of  preserving,  special 
to  the  different  invertebrate  groups  ;  and  '  taxidermy ' 
is  in  itself  a  complicated  art.  I  will  merely  men- 
tion one  or  two  general  points.  A  specimen  in 
almost  every  group  is  of  infinitely  greater  scientific 
value  if  it  be  preserved  entire  with  its  soft  parts. 
Por  this  purpose  the  most  usual  plan  is  to  place  it 
at  once  in  spirit  of  wine  diluted  to  about  proof 
Care  must  be  taken  not  to  put  too  many  specimens 


262  THE  DEPTHS  OF  THE  SEA.  [chap.  vi. 

together  ia  one  jar,  or  they  will  very  shortly  become 
discoloured ;  and  the  jars  ought  to  be  looked  to  care- 
fully and  the  spirit  tested,  and  if  necessary  renewed 
after  they  have  been  set  aside  for  a  day  or  two,  asj 
sea  animals  contain  a  large  quantity  of  water.     laj 
hot  weather,  and  if  the  specimens  be  bulky,  it  is] 
often   better   to    use    strong    spirit.      The    ordinary] 
methylated   spirit  of  commerce   answers  sufficiently] 
well  for  ordinary  purposes,  though  if  a  specimen  boj 
reserved  for  minute  dissection,  I  prefer  using  pure, 
or  even  absolute  alcohol. 

For  very  delicate  transparent  objects, — such  as] 
salpae,  siphonophora,  polycystina,  &c.,  —  Goadby' 
solution  seems  to  be  preferable:  but  do  what  w( 
may,  a  preserved  specimen  of  one  of  these  lovel] 
objects  is  a  mere  caput  mortumriy  a  melancholy  sug- 
gestion of  its  former  beauty ;  good  only  for  the 
demonstration  of  anatomical  structure. 

In  preserving  marine  animals  dry,  as  much  of 
the  soft  parts  should  be  removed  as  possible,  and 
replaced  by  tow  or  cotton,  and  the  object  to  be 
dried  should  be  steeped  in  several  changes  of  fresh 
water  to  get  rid  of  the  whole  of  the  salt,  and  then 
dried  very  thoroughly  and  not  too  quickly.  Every 
specimen,  whether  dry  or  in  spirit,  should  be  labelled 
at  once,  with  the  number  under  which  this  particular 
dredging  is  entered  in  the  dredger's  note-book.  It 
is  wonderful  how  soon  things  get  into  confusion 
if  this  be  not  rigorously  attended  to.  The  small 
paper  tickets  with  a  fancy  margin  and  gummed  on 
the  back,  which  haberdashers  use  for  ticketing 
their  goods,  are  to  be  had  of  all  wholesale 
stationers  at  nominal  prices,  and  they  are  very  con- 


CHAP.  VI.]  DEEP-SEA  DREDGING.  263 

venient.  Their  great  disadvantage  is  that  if  the 
bottles  on  which  they  are  fixed  get  wet  they  are  apt 
to  come  off. 

Pencils  are  sold  by  seed-merchants  for  writing  on 
tallies  which  are  to  be  exposed  to  rain.  Perhaps 
the  safest  plan  is  to  mark  the  number  and  date  with 
such  a  pencil  on  a  shred  of  parchment  or  parch- 
ment paper,  and  put  it  into  the  bottle.  This  may 
seem  a  trifling  detail,  but  so  great  inconvenience 
constantly  arises  from  carelessness  in  this  matter, 
that  I  feel  sure  of  the  sympathy  of  all  who  are 
interested  in  the  scientific  aspect  of  dredging  when 
I  insist  upon  the  value  of  accurate  labelling. 

It  is  of  even  greater  importance  that  certain 
circumstances  relating  to  every  individual  haul  of 
the  dredge  should  be  systematically  noted,  either 
in  the  dredger's  diary,  or  on  a  special  form  prepared 
for  the  purpose.  The  precise  position  of  the  station 
ought  to  be  defined  in  shore  dredging  by  giving 
the  distance  from  shore  and  the  bearings  of  some 
fixed  objects;  in  ocean  dredging  by  noting  accurately 
the  latitude  and  longitude.  In  the  '  Lightning,'  in 
1868,  we  dredged  at  a  station  about  100  miles  to 
the  north  of  the  Butt  of  the  Lews,  and  came  upon 
a  singular  assemblage  of  interesting  animal  forms. 
Next  year,  in  the  '  Porcupine,'  we  were  anxious  to 
try  again  the  same  spot  to  procure  some  additional 
specimens  of  a  sponge  which  we  were  studying. 
The  position  had  been  accurately  given  in  the  log 
of  the  '  Lightning,'  and  the  first  haul  at  a  depth  of 
upwards  of  half  a  mile  gave  us  the  very  same  group 
of  forms  which  we  had  taken  the  year  before.  On 
our  return  Captain  Calver  again  dropped  the  dredge 


264  THE  DEPTHS  OF  THE  SEJ.  [guap.  vi. 

upon  the  same  spot,  with  like  success.  The  depth 
in  fathoms  should  be  carefully  noted,  as  a  most  im- 
portant element  in  determining  the  conditions  of  life 
and  distribution  of  species;  and  the  nature  of  the 
bottom — whether  mud,  sand,  or  gravel;  and  if  the 
latter,  it  is  well  to  state  the  nature  and  composition 
of  the  pebbles,  and  if  possible  the  source  from  which 
they  may  probably  have  been  derived.  Now  that 
we  have  in  the  Miller-Casella  thermometer  a  reliable 
instrument  for  this  purpose,  the  bottom  temperature 
ought  always  to  be  noted.  This  is  important  whether 
in  shallow  or  in  deep  water.  In  shallow  water  it 
gives  a  datum,  for  determining  the  range  of  annual 
variation  of  temperature  which  can  be  endured  by 
certain  species ;  and  at  great  depths  it  is  even  more 
important,  as  we  are  now  aware  that,  owing  to  the 
movement  of  masses  of  water  at  different  tempera- 
tures in  various  directions,  totally  different  condi- 
tions of  climate  may  exist  in  deep  water  within  a 
few  miles  of  one  another,  and  the  limits  of  these 
conditions  can  only  be  determined  by  direct  experi- 
ment. It  is  important  when  determining  the  bottom 
temperature  to  note  also  the  temperature  of  the 
surface  of  the  sea,  the  temperature  of  the  air,  the 
direction  and  force  of  the  wind,  and  the  general 
atmospheric  conditions.  If  the  dredger  be  purely  a 
zoologist,  having  no  particular  interest  in  special 
physical  problems,  it  will  still  be  well  worth  his 
while  to  make  all  the  observations  indicated  and  to 
publish  the  results.  These  then  pass  into  the 
hands  of  physical  geographers,  to  whom  all  trust- 
worthy additions  to  the  myriad  of  data  which  are 
required   to   arrive  at  a  true  generalization  of  the 


CHAP.  VI. J  DEEF-SEA  DREDOING.  265 

phenomena  of  the  distribution  of   temperature   are 
most  acceptable. 

At  the  Birmingham  Meeting  of  the  British  Asso- 
ciation in  1839  an  important  committee  was  ap- 
pointed "for  researches  with  the  dredge,  with  a 
view  to  the  investigation  of  the  marine  zoology  of 
Great  Britain,  the  illustration  of  the  geographical 
distribution  of  marine  animals,  and  the  more 
accurate  determination  of  the  fossils  of  the  plio- 
cene period :  under  the  superintendence  of  Mr. 
Gray,  Mr.  Eorbes,  Mr.  Goodsir,  Mr.  Patterson,  Mr. 
Thompson  of  Belfast,  Mr.  Ball  of  Dublin,  Dr.  George 
Johnston,  Mr.  Smith  of  Jordan  Hill,  and  Mr.  A. 
Strickland."  The  appointment  of  this  committee 
may  be  regarded  as  the  initiation  of  the  systematic 
employment  of  this  method  of  research.  Edward 
Eorbes  was  the  ruling  spirit,  and  under  the  genial 
influence  of  his  contagious  enthusiasm  great  pro- 
gress was  made  during  the  next  decade  in  the  know- 
ledge of  the  fauna  of  the  British  seas,  and  many 
wonderfully  pleasant  days  were  spent  by  the  original 
committee  and  by  many  others  who,  from  year  to 
year,  were  '  added  to  their  number.'  Every  annual 
report  of  the  British  Association  contained  commu- 
nications from  the  English,  the  Scottish,  or  the  Irish 
branches  of  the  committee,  and  in  1850  Edward 
Eorbes  submitted  its  first  general  report  on  British 
marine  zoology.  This  report,  as  might  have  been 
anticipated  from  the  eminent  qualifications  of  the 
reporter,  was  of  the  highest  value ;  and  taken  along 
with  his  remarkable  memoirs  previously  published, 
"  on  the  distribution  of  the  MoUusca  and  Eadiata 
of  the  ^gean  Sea,"  and  ''on  the  geological  relations 


266        •  THE  DEPTHS  OF  THE  SEA.  [chap.  vi. 

of  the  existino?  Pauna  and  Flora  of  the  British 
Isles,"  may  be  said  to  mark  an  era  in  the  progress 
of  human  thought. 

After  enumerating  various  additions  to  our  know- 
ledge of  the  distribution  of  marine  invertebrata 
within  the  British  area  which  were  still  to  be  de- 
sired, Eorbes  concludes  his  report  with  the  following 
sentence:  "And  lastly,  though  I  fear  the  consum- 
mation, however  devoutly  wished  for,  is  not  likely 
soon  to  be  effected,  a  series  of  dredgings  between 
the  Zetland  and  the  Pseroe  Isles,  where  the  greatest 
depth  is  under  700  fathoms,  would  throw  more  light 
on  the  natural  history  of  the  North  Atlantic  and 
on  marine  zoology  generally  than  any  investigation 
that  has  yet  been  undertaken/' 

To  Forbes' s  general  report  succeeded  many  reports 
from  the  different  sections  into  which  from  year  to 
year  the  committee  divided  itself.  Among  these  I 
may  mention  particularly  the  very  excellent  work 
done  by  the  Belfast  dredging  committee,  communi- 
cated to  several  meetings  of  the  Association  by  the 
late  Mr.  George  C.  Hyndman;  the  reports  of  the 
Dublin  committee  by  the  late  Professor  Kinahan 
and  Professor  E.  Perceval  Wright;  the  important 
lists  of  the  fauna  of  the  East  Coast  of  England  re- 
ported on  behalf  of  the  Natural  History  Society  of 
Northumberland,  Durham,  and  Newcastle-upon-Tyne, 
and  of  the  Tyne-side  Naturalists'  Field  Club,  by  Mr. 
Henry  T.  Mennell  and  Mr.  G.  S.  Brady ;  and  lastly 
the  invaluable  reports  on  the  marine  fauna  of  the 
Hebrides  and  Shetland,  compiled  at  an  extraordinary 
expense  of  labour,  discomfort,  and  privation — doubt- 
less with  an  immediate  guerdon  of  infinite  enjoyment 


CHAP,  vj.]  DEEP-SEA  DREDGING.  267 

— through  many  years,  by  Mr.  Gwyn  Jeffreys,  Mr. 
Barlee,  the  Eev.  A.  Merle  Norman,  and  Mr.  Edward 
Waller,  and  communicated  to  the  Transactions  of  the 
Association  from  1863  to  1868.  The  dredging  com- 
mittees of  the  British  Association,  combining  the 
pursuit  of  knowledge  with  the  recreation  of  their 
summer  holidays,  may  be  said  to  have  worked  out  the 
fauna  of  the  British  area  down  to  the  100-fathom 
line,  for  the  dredger  is  now  rarely  rewarded  by  a 
conspicuous  novelty,  and  must  be  contented  that  the 
greater  number  of  his  additions  to  the  British  list 
are  confined  to  the  more  obscure  groups. 

Meanwhile  some  members  of  the  dredging  com- 
mittee and  their  friends  who  had  time  and  means 
at  their  disposal  pushed  their  operations  farther 
a-field,  and  did  good  service  on  foreign  shores.  In 
1850,  Mr.  Mac  Andrew  published  many  valuable  notes 
on  the  lusitanian  and  mediterranean  faunae ;  and 
in  1856,  at  the  request  of  the  biological  section  of 
the  British  Association,  he  submitted  to  the  Chel- 
tenham meeting  a  general  "report  on  the  marine 
testaceous  mollusca  of  the  North-east  Atlantic  and 
neighbouring  seas,  and  the  physical  conditions  affect- 
ing their  development."  The  field  of  these  arduous 
labours  extended  from  the  Canary  Islands  to  the 
North  Cape,  over  about  43  degrees  of  latitude,  and 
many  species  are  recorded  by  him  as  having  been 
dredged  at  depths  between  160  and  200  fathoms  off 
the  coast  of  Norway.  Subsequently,  Mr.  Gwyn 
Jeffreys  went  over  some  of  the  same  ground,  and 
made  many  additions  to  the  lists  of  his  predecessors. 

Nor  were  our  neighbours  idle.  In  Scandinavia 
a  brilliant  triumvirate — Loven  of  Stockholm,  Steen- 


268  TEE  DEPTHS  OF  THE  SEA.  [chap.  vr. 

strup  of  Copenhagen,  and  Michael  Sars  of  Chris- 
tiania — were  making  perpetual  advances  in  the 
knowledge  of  marine  zoology.  Milne-Edwards  was 
illustrating  the  fauna  of  the  coast  of  Prance,  and 
Philippi,  Grube,  Oscar  Schmidt,  and  others  were 
continuinoj  in  the  Mediterranean  and  the  Adriatic 
the  work  so  well  begun  by  Donati,  Olivi,  E^isso, 
Delle  Chiage,  Poll,  and  Cantraine;  while  Deshayes 
and  Lacaze  Duthiers  illustrated  the  fauna  of  the 
coast  of  Algeria.  So  much  progress  had  already 
been  made  at  home  and  abroad,  that  in  the  year 
1854  Edward  Porbes  considered  that  the  time  had 
arrived  for  giving  to  the  public,  at  all  events  a  pre- 
liminary sketch  of  the  fauna  of  the  European  seas 
— a  work  which  he  commenced,  but  did  not  live  to 
finish. 

I  need  scarcely  say  that  these  operations  of  the 
British  Association  dredging  committees  were  carried 
on  generally  under  the  idea  that  at  the  100-fathom 
line,  by  which  amateur  work  was  practically  limited, 
they  approached  the  zero  of  animal  life — a  notion 
which  was  destined  to  be  gradually  undermined  and 
finally  completely  overthrown.  Prom  time  to  time, 
however,  there  were  not  wanting  men  of  great  skill 
and  experience  to  maintain,  with  Sir  James  Clark 
Ross,  that  "  from  however  great  a  depth  we  may  be 
enabled  to  bring  up  the  mud  and  stones  of  the  bed 
of  the  ocean,  we  shall  find  them  teeming  with  animal 
life."  Prom  the  very  general  prevalence  of  the 
negative  view  there  was  little  to  stimulate  to  the 
investigation  of  the  bottom  at  great  depths,  and  data 
gathered  very  slowly. 

I    have  already   referred    (p.   18  et   infra)  to  the 


CHAP.  VI.]  *        DEEP-SEA  DREDGING.  2G9 

observations  of  Sir  John.  Ross  in  1818,  of  Sir 
James  Ross  in  1810,  and  of  Mr.  Harry  Goodsir 
in  1845.  In  the  year  1844  Professor  Loven  con- 
tributed a  paper,  ''  on** the  bathymetrical  distribu- 
tion of  submarine  life  on  the  northern  shores  of 
Scandinavia,"  to  the  British  Association.  He  says, 
**  With  us  the  region  of  deep-sea  corals  is  character- 
ized in  the  south  by  Oculina  ramea  and  Terehratula^ 
and  in  the  north  by  Astrophyton,  Cldaris,  Spatangiis 
ptirpweus  of  an  immense  size,  all  living;  besides  Gor- 
gonice  and  the  gigantic  Alcyonmm  arhoreum,  which 
continues  as  far  down  as  any  fisherman's  line  can  be 
sunk.  As  to  the  point  where  animal  life  ceases,  it 
must  be  somewhere,  but  with  us  it  is  unknown."^ 

In  1863  the  same  naturalist,  referring  to  the 
result  of  the  Swedish  Spitzbergen  expedition  of 
1861,  when  mollusca,  Crustacea,  and  hydrozoa  Avere 
brought  up  from  a  depth  of  1,400  fathoms,  expresses 
the  remarkable  opinion,  which  later  investigations 
appear  generally  to  support,  that  at  great  depths, 
wherever  the  bottom  is  suitable,  "  a  fauna  of  the 
same  general  character  extends  from  pole  to  pole 
through  all  degrees  of  latitude,  some  of  the  species 
of  the  fauna  being  very  widely  distributed."  ^ 

In  1846  Keferstein  mentions  having  seen  in  Stock- 
holm a  whole  collection  of  invertebrate  animals— 
Crustacea,  phascolosoma,  annelids,  spatangus,  myrio- 
trochus,  sponges,  bryozoa,  rhizopoda,  &c. — taken  at 
a  depth  of  1,400  fathoms  during  O.  Torell's  Spitz- 

^  Eeport  of  the  Fourteenth  Meeting  of  the  British  Association,  held 
at  York  in  September  1844.     (Transactions  of  the  Sections,  p.  50.) 

2  Forh.  ved  de  Skand.  l^aturforskeres  Mode  i  Stockholm,  18G3, 
p  384. 


270  THE  DEPTHS  OF  THE  SEA.  [chap.  vr. 

bergen  expedition  in  the  *  Maclean  nets,'  and  in 
the  same  year  O.  Torell  alludes  to  one  of  the  crus- 
taceans from  that  depth  being  of  a  bright  colour/ 

In  184^6  Captain  Spratt,  R.N.,  dredged  at  a  depth' 
of  310  fathoms  forty  miles  east  of  Malta  a  number 
of  mollusca  which  have  been  subsequently  examined 
by  Mr.  Gwyn  Jeffreys  and  found  to  be  identical  with 
species  dredged  at  considerable  depths  in  the  north- 
ern seas  during  the  'Porcupine'  expedition.  The 
list  includes  Leda  pellucida,  Philippi  ;  Leda  acu- 
minata, Jefpreys  ;  Dentalium  agile,  Sars  ;  Sela 
tenella,  Jepfreys  ;  Eulima  stenostoma,  Jeppreys  ; 
Trophon  barvicensis,  Johnston  ;  JPleurotoma  cari- 
natum,  Bivona;  and  I^hiline  quadrata,  S.  V.  Wood. 
Captain  Spratt  observes  that  he  *' believed  animal 
life  to  exist  much  lower,  although  the  general 
character  of  the  -^gean  is  to  limit  it  to  300j 
fathoms."  ^ 

In  1850  Michael  Sars,  in  an  account  of  a  zoolo-1 
gical  excursion  in  Einland  and  Loffoten,  expressed 
his  conviction  that  there  is  a  full  development  of  | 
animal  life  at  considerable  depths  off  the  Norwegian 
coast.  He  enumerated  nineteen  species  taken  by 
himself  at  depths  beyond  300  fathoms,  and  pointed 
out  that  two  of  these  were  the  largest  species 
known  of  their  respective  genera.^ 

^  Nachrichten  der  Kdnigl.  GeRellsch.  der  Wissensch.  zu  Gottingen. 
Marz  1846. 

2  On  the  Influence  of  Temperature  upon  the  Distribution  of  the 
Fauna  in  the  ^gean  Sea.  Eeport  of  the  Eighteenth  Meeting  of  the 
British  Association,  1848. 

3  Beretning  om  en  i  Sommeren,  1849,  foretagen  zoologisk  Eeise  i 
Lofoten  og  Finmarken.     Christiania,  1850. 


CHAP.  VI.]  DEEP-SEA  DREDGINO.  271 

I  have  referred  likewise  (p.  26)  to  Professor 
Fleeming  Jenkin's  notes  on  the  living  animals 
attached  to  the  Mediterranean  cahle  at  a  depth  of 
1,200  fathoms,  and  to  the  results  of  Dr.  Wallich's 
special  investigations  on  hoard  H.M.S.  '  Bull-dog.' 

In  a  general  review  of  the  progress  of  knowledge  as 
to  the  conditions  of  life  at  great  depths,  these  investi- 
gations deserve  special  notice,  as,  even  if  they  must 
still  he  regarded  as  somewhat  unsatisfactory,  they 
distinctly  mark  a  stage  in  advance.  Although,  from 
the  imperfection  of  the  means  at  his  disposal,  Dr. 
Wallich  could  not  hring  home  evidence  sufficient 
absolutely  to  satisfy  others,  he  was  convinced  in  his 
own  mind  from  what  he  saw,  that  living  beings  high 
in  the  scale  of  organization  might  exist  at  any  depth 
in  the  ocean;  he  expounded  clearly  and  forcibly 
the  train  of  reasoning  which  led  him  to  this  belief, 
and  subsequent  events  have  amply  justified  his  con- 
clusion. The  space  at  my  disposal  will  not  allow 
me  to  quote  and  discuss  Dr.  Wallich's  arguments,  in 
some  of  which  I  thoroughly  concur,  while  from 
others  I  am  compelled  to  dissent.  The  facts  w^ere 
most  important,  and  their  significance  increases  now 
that  they  are  fully  confirmed  and  illustrated  by  ope- 
rations on  a  large  scale.  In  lat.  59°  27^  N.,  long. 
26°  4r  W.,  a  depth  of  1,260  fathoms  having  been 
previously  ascertained,  "  a  new  kind  of  deep-sea  dredge 
was  lowered ;  but  in  consequence  of  its  partial  failure, 
a  second  apparatus  (namely,  the  conical  cup)  was  em- 
ployed, fifty  fathoms  of  line  in  excess  of  the  recorded 
depth  being  paid  out  in  order  to  ensure  the  unchecked 
descent  and  impact  of  the  instrument  at  the  bottom. 
The  dredge  had  already  brought  up  a  small  quantity 


272 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VI. 


of  unusually  fine  globigerina  deposit  and  some  small 
stones.     The  second  instrument  came  up  quite  full  of 
the  deposit ;  but  it  was  neither  so  free  from  amorphous 
matter,  nor  did  it  contain  any  of  the  small  stones. 
Adhering,  however,  to  the  last  fifty  fathoms  of  line, 
which  had  rested  on  the  ground  for  several  moments, 
were  thirteen  ophiocomse,  varying  in  diameter  across 
the  arms  from  two  to  five  inches."     The  misfortune] 
of  these  star-fishes  was  that  they  did  not  go  into  the] 
dredge ;  had  they  done  so,  they  would  at  once  have 
achieved  immortality.     Noio,  of  course,  we  have  no 
doubt  that  they  came  from  the   bottom,    but   their  j 
irregular  mode  of  appearance  left,  in  the  condition 
of  knowledge  and  prejudice  at  the  time,  a  loophole 
for  scepticism. 

In  three  soundings,  including  that  in  which  the 
star-fishes  were  obtained,  at  1,260,  1,913,  and  1,268 
fathoms   respectively,  ''  minute  cylindrical  tubes  oc- 
curred, varying  from  one-eighth  to  half  an  inch  ini 
length,  and  from  one-fiftieth  to  one-twentieth  of  ani 
inch  in  diameter.     These  were  built  up  almost  ex-i 
clusively  of  very  small  globigerina  shells,  and  still 
more  minute  calcareous  debris   cemented  together."] 
.  .  .  .  "The  shells  forming  the  outer  layer  of  the  I 
tubes   were   colourless,    and    freed    of    all    sarcodic^ 
matter;    but   the   internal   surface    of    the    tubular] 
cylinder  was  lined  with  a  delicate  yet  distinct  layer] 
of  reddish   chitine."     Er.    Wallich   is    satisfied  that] 
these  tubes  contained  some  species  of  annelid.     "  In] 
a  sounding  taken  in  lat.  63°  SV  N.,  long.  13°  45'  W.,! 
in   682    fathoms,  a  portion  of  a   serpula-tuhQ  five- 
twelfths   of  an  inch   in   length,    and    about    three- 
sixteenths  of  an  inch  in  diameter,   belonging   to   a 


CHAP.  VI.]  DEEP-SEA  D HEDGING.  273 

known  species,  came  up  in  such  a  condition  as  to 
leave  no  room  for  doubt  that  it  had  been  broken 
off  the  rock  or  stone  to  which  it  was  adherent  by 
the  sounding-machine,  and  that  tlie  animal  was 
living ;  whilst  a  smaller  Serpula  and  a  cluster  of 
apparently  living  polyzoa  were  adherent  to  its  ex- 
ternal surface.  A  minute  Spirorhis  also  occurred  in 
this  sounding.  Lastly,  from  a  depth  of  145  fathoms, 
within  a  short  distance  of  the  south  coast  of  Iceland, 
a  couple  of  living  amphipod  crustaceans  were  ob- 
tained, and  a  filamentous  annelid  about  three-quarters 
of  an  inch  in  lengtli."  Basing  his  opinion  principally 
upon  these  facts.  Dr.  Wallich,  in  conclusion,  submits 
several  propositions,  the  two  most  important  of  which 
may  be  said  to  anticipate  the  more  remarkable  results 
of  our  subsequent  work.  As  the  others  are  merely 
founded  upon  what  I  conceive  to  be  a  mistaken 
determination  of  the  animal  species  captured,  I  need 
not  now  quote  them.^ 

"1.  The  conditions  prevailing  at  great  depths, 
although  differing  materially  from  those  w^hicli  pre- 
vail at  the  surface  of  the  ocean,  are  not  incompatible 

with  the  maintenance  of  animal  life. 

*  *  *  *  *       »      *  * 

"5.  The  discovery  of  even  a  single  species,  living- 
normally  at  great  depths,  warrants  the  inference  that 
the  deep  sea  has  its  own  special  fauna,  and  that  it  has 
always  had  it  in  ages  past ;  and  hence  that  many 
fossiliferous  strata  heretofore  regarded  as  having  been 

^  And  see  Professor  Sars'  "  Bemoerkningen  over  (let  dyriske  Livs 
Udbredning  i  llavets  Dybder,  med  soerligt  Hensyn  til  et  af.  Dr. 
Wallich  i  London  niylig  udkommet  Skrift,  *  The  ^^orth  Atlantic  Sea- 
bed.' "     (Vid.-Selsk.  Forhandlinger  for  1864.) 

T 


274  THE  DEPTHS  OF  THE  SEA.  [chap.  vi. 

deposited  in  comparatively  shallow  water,  have  been 
deposited  at  great  depths."^ 

In  1864,  Professor  Sars  made  a  great  addition  to 
his  list  of  species  from  depths  of  from  200  to  300 
fathoms  off  the  coast  of  Norway.  He  remarks  : — 
"  The  species  of  animals  named  are  not  certainly  very 
numerous  (92),  yet  when  we  consider  that  most  of 
them  were  taken  accidentally,  attached  to  the  lines 
of  the  fishermen,  and  that  only  in  a  few  instances  the 
dredge  was  used  at  these  great  depths,  it  will  be  seen 
that  there  is  a  very  interesting  field  here  for  the 
Naturalist  furnished  with  the  proper  instruments." 

In  1868  Professor  Sars  made  a  still  further  addi- 
tion to  the  deep-sea  fauna  of  the  Norwegian  Seas ; 
an  addition  so  important,  that  he  remarks  'Hhat  it 
is  so  great  as  to  give  a  tolerably  complete  idea  of 
the  general  fauna  of  these  coasts."  This  increase  of 
knowledge.  Professor  Sars  states,  is  almost  entirely 
due  to  the  indefatigable  labours  of  his  son,  G.  O. 
Sars,  an  Inspector  of  Eisheries  under  the  Swedish 
Government,  who  took  advantage  of  the  opportuni- 
ties given  by  his  occupation  to  dredge  down  to  450 
fathoms  on  some  parts  of  the  coast,  and  among  the 
Loffoten  Islands.  Sars  likewise  acknowledges  many 
contributions  from  his  old  fellow-labourers,  Danielssen 
and  Keren.  The  number  of  species  from  depths  be- 
tween 250  and  450  fathoms  on  the  coast  of  Norway 
now  reaches  427,  thus  distributed  : — 

Species. 

^    ,  f  Rhizopoda Qd^ 

Protozoa ^  r)    •/? 

(  roritera 5 

—     73 
1   ^N'orth  Atlantic  Sea  bed,  p.  154. 


CHAP.  VI.] 


DEEP-SEA  DREDGING. 


275 


Coelenterata  .     . 


Echinodermata  . 


/  Hydrozoa 
I  Anthozoa 


Species. 

2 
20 


'Crinoidea 

J  Asteridea,  including  Opliiuridea 

j  Echinoidea 

^  Holotliuridea 


Vermes 


r  Gephyrea 
I  Annelida 


Mollusca 


Arthropod  a  .     .     . 


Polyzoa .     . 

Tunicata  . 
-    Brachiopoda 

Conchifera  . 
[  Cephalophora 


(  Arachnida 
1  Crustacea 


2 

21 

5 

8 

6 
51 

35 

4 

4 

37 

53 

1 

105 


22 


36 


57 


133 


106 


Of  these  24  protozoa,  3  echinoderms,  and  13  mol- 
lusca are  from  a  depth  of  450  fathoms.  Professor 
Sars  adds  :  "  We  may  say,  according  to  our  present 
information,  that  the  true  deep-water  belt  commences 
at  about  100  fathoms.  The  greater  number  of  deep- 
sea  species  begin  to  appear  then,  though  sparingly, 
and  they  increase  in  number  of  individuals  as  we 
descend  to  300  fathoms,  or  in  some  cases  to  450, 
j^wheji  investigations  have  been  carried  so  far.  To 
what  depth  this  belt  extends,  or  whether  there  is 
another  below  it  of  a  difPerent  character,  is  not  yet 
known."  ^ 

In  the  year  1864,  M.  Barboza  du  Bocage,  Director 

^  Fortsatte   Bemaerkninger   over   det  dyriske  Livs    Udbredning  i 
Havets  Dybder,  af  M.   Sars.      (Vidensk.-Selsk.      Forhandlinger  for 

18G8.) 

t2 


276  THE  DEPTHS  OF  THE  SEA.  [chap.  vi. 

of  the  Natural  History  Museum  of  Lisbon,  greatly 
surprised  the  zoological  world  by  a  notice  of  the 
occurrence  on  the  coast  of  Portugal  of  whisps  of 
silicious  spicules  resembling  those  of  the  ITya- 
lo7iema  of  Japan.  ^  They  were  brought  up  by  the 
Setubal  shark-fishers,  who,  it  seemed — an  equally  sin- 
gular circumstance— plied  their  vocation  at  a  depth 
of  500  fathoms.  Professor  Percival  Wright,  anxious 
to  ascertain  the  full  history  of  the  case  and  to 
get  Ilyalonema  in  a  fresh  state,  went  to  Lisbon 
in  the  autumn  of  1868,  and  with  the  assistance  of 
Professor  du  Bocage  and  some  of  his  friends  procured 
at  Setubal  an  open  boat  and  a  crew  of  eight  men, 
with  "  600  fathoms  of  rope,  the  dredge,  lots  of  hooks 
and  bait,  and  provisions  for  a  couple  of  days.  Leav- 
ing the  port  of  Setubal  a  little  before  five  o'clock  in 
the  evening,  we,  after  a  fair  night's  sailing,  reached 
what  the  fishermen  signed  to  me  to  be  the  edge  of 
the  deep-sea  valley,  where  they  were  in  the  habit 
of  fishing  for  sharks,  and  there,  while  thus  engaged, 
they  had  found  the  Ilyalonema.  It  was  now  about 
five  o'clock  in  the  morning ;  and  the  men,  having  had 
their  breakfast,  put  the  boat  up  to  the  wind,  and  let 
down  the  dredge  ;  before  it  reached  the  bottom,  about 
480  fathoms  of  rope  were  run  out,  some  thirty  more 
were  allowed  for  slack,  and  then  we  gently  drew  it — 
by  hoisting  a  small  foresail— for  the  distance  of  about 
mile  along  the  bottom.  It  required  the  united 
efforts  of  six  men,  hauling  the  line  hand  over  hand, 
with  the  assistance  of  a  double  pulley-block,  to  pull 
in  the  dredge  :  the  time  thus  occupied  was  just  an 

^  Proceedings  of  the  Zoological  Society  of  London  for  the  Year 
1S64,  p.  2C)5. 


CHAP.  VI.]        '  DEEP-SEA  DREDGING.  277 

hour.  The  dredge  was  nearly  full  of  a  tenacious 
yellowish  mud,  through  which  sparkled  innumerable 
long  spicules  of  the  Hyalonema ;  indeed,  if  you  drew 
your  fingers  slowly  through  the  mud,  you  would 
thereby  gather  a  handful  of  these  spicules.  One 
specimen  of  Hyalonema^  with  the  long  spicules  in- 
serted into  the  mud  and  crowned  with  its  expanded 
sponge-like  portions,  rewarded  my  first  attempt  at 
dredging  at  such  a  depth. '^  ^  This  dredging  is  of 
especial  interest,  for  it  shows  that  although  difficult 
and  laborious,  and  attended  with  a  certain  amount  of 
risk,  it  is  not  impossible  in  an  open  boat  and  with  a 
crew  of  alien  fishermen,  to  test  the  nature  of  the 
bottom  and  the  character  of  the  fauna,  even  to  tho 
great  depth  of  500  fathoms. 

In  the  year  1868,  Count  L.  P.  de  Pourtales,  one 
of  the  officers  employed  in  the  United  States  Coast 
Survey  under  Professor  Pierce,  commenced  a  series  of 
deep  dredgings  across  the  gulf-stream  off  the  coast  of 
Florida ;  which  were  continued  in  the  following  year, 
and  were  productive  of  most  valuable  results.  Many 
important  memoirs  at  the  hands  of  Count  Pourtales, 
Mr.  Alexander  Agassiz,  Mr.  Theodore  Lyman  and 
others,  have  since  enriched  the  pages  of  the  Bulletin  of 
the  Museum  of  Comparative  Zoology,  and  have  greatly 
extended  our  knowledge  of  the  deep-sea  gulf-stream 
fauna  ;  and  much  information  has  been  gained  as  to 
the  nature  of  the  bottom  in  those  regions,  and  the 
changes  which  are  there  taking  place.  Unfortunately 
a  large  part  of  the  collections  were  in  Chicago  in  the 

^  Notes  on  Beep-sea  Dredging,  by  Edward  Percival  W^right,  M.D., 
F.L.S.,  from  the  Annals  and  Magazine  of  Natural  History  for 
December  1868. 


278  THE  DEPTHS  OF  THE  SEJ.  [chap.  vi. 

hands  of  Dr.  Stimpson  for  description  at  the  time 
of  the  terrible  catastrophe  which  laid  a  great  part 
of  that  citv  in  ashes,  and  were  destroyed ;  hut,  hj 
a  sinsnlarlv  fortunate  accident,  our  colleasrue  Mr. 
Gwrn  JeflPreys  happened  to  he  in  Chicago  shortly 
before  the  fire,  and  Dr.  Stimpson  gave  him  a  series 
of  duplicates  of  the  moUusca  for  comparison  with 
the  species  dredged  in  the  '  Porcupine,'  and  a  valu- 
able remnant  was  thus  saved.  M.  de  Pourtales, 
writing  to  one  of  the  editors  of  SLlliman's  Journal 
on  the  20th  of  September,  18G8,  savs :  ''  The  dredg- 
ings  were  made  outside  the  Florida  reef,  at  the 
same  time  as  the  deep-sea  soundings,  in  lines  ex- 
tending from  the  reef  to  a  depth  of  about  400  to 
500  fathoms,  so  as  to  develop  the  figure  of  the 
bottom,  its  formation  and  fauna.  Six  such  liaes 
were  sounded  out  and  dredged  over  in  the  space 
comprised  between  Sandy  Bay  and  CoflSji's  Patches. 
All  of  them  agree  nearly  in  the  following  particu- 
lars:  from  the  reef  to  about  the  100-fathom  line, 
four  or  five  mUes  off,  the  bottom  consists  chiefly 
of  broken  shells  and  very  few  corals,  and  is  rather 
barren  of  life.  A  second  region  extends  from  the 
neighbourhood  of  the  100-fathom  line  to  about  300 
fathoms;  the  slope  is  very  gradual,  particularly 
between  100  and  200  fathoms ;  the  bottom  is  rocky, 
and  is  inhabited  by  quite  a  rich  fauna.  The  breadth 
of  this  band  varies  from  ten  to  twenty  miles.  The 
third  region  begins  between  250  and  300  fathoms, 
and  is  the  great  bed  of  foraminifera  so  widely  ex- 
tended over  the  bottom  of  the  ocean 

"From  the  third  region  the  dredges  brought  up 
fewer  though  not   less   interesting    specimens,    the 


CHAP.  VI.]  DEEP -SEA  DREDGING.  279 

chief  of  which  was  a  new  crinoid  belonging  to  the 
genus  Bourguettlcrinus  of  D'Orbigny  ;  it  may  even 
be  the  species  named  by  him  _S.  hotessieri,  which 
occurs  fossil  in  a  recent  formation  in  Guadaloupe, 
but  of  which  only  small  pieces  of  the  stem  are 
known.  I  obtained  half-a-dozen  specimens  between 
230  and  300  fathoms,  unfortunately  more  or  less 
injured  by  the  dredge.  The  deepest  cast  made  was 
in  517  fathoms ;  it  gave  a  very  handsome  Mopsea 
and  some  annelids."  ^ 

The  results  of  the  '  Lightning '  cruise  in  1868,  in 
which  dredging  was  successfully  carried  dowTi  to 
650  fathoms,  have  already  been  recorded. 

In  the  summer  of  187o/Mr.  Marshall  Hall,  F.G.S., 
with  an  interest  in  science  which  is  unfortunately 
rare  among  yachtsmen,  devoted  his  yacht  '  Xorna ' 
to  deep-sea  dredging  work  during  a  cruise  along 
the  coasts  of  Portugal  and  Spain.  If  we  may  judge 
by  several  preliminary  sketches  which  have  from 
time  to  time  appeared  at  the  hands  of  Mr.  Saville 
Kent,  the  collections  made  during  this  expedition 
must  have  been  extensive  and  valuable. ^ 

The  last  researches  in  order  of  time  are  those  eon- 
ducted  on  board   H.M.S.    'Porcupine'   in   1869  and 

1870.  With  the  use  of  a  Government  surveying 
ship  well  found  in  all  necessary  appliances  every- 
thing was  in  our  favour,  and,  as  has  been  already 
told,  dredging  was  carried  down  to  2,435  fathoms ; 

^  American  Journal  of  Science,  vol.  xcvi.  p.  413. 

^  Zoological  Eesults  of  the  1870  Dredging  Expedition  of  the  Yacht 
*Xorna*  oJGf  the  coasts  of  Spain  and  Portugal,  communicated  to  the 
Biological  Section  of  the  British  Association,  Edinburgh,  August  «, 

1871.  Xature,  vol.  iv.  p.  456. 


280 


THE  DEPTHS  OF  THE  SEA. 


[chap.  V 


and  the  fact  that  there  is  an  abundant  and  charac- 
teristic invertebrate  fauna  at  all  depths  Avas  placed 
beyond  further  question.  As  yet,  little  more  can  be 
said.  A  grand  new  field  of  inquiry  has  been  opened 
up,  but  its  culture  is  terribly  laborious.  Every  haul 
of  the  dredge  brings  to  light  new  and  unfamiliar 
forms — forms  which  link  themselves  strauE^elv  with 
the  inhabitants  of  past  periods  in  the  earth's  history ; 
but  as  yet  we  have  not  the  data  for  generalizing  the 
deep-sea  fauna,  and  speculating  on  its  geological 
and  biological  relations ;  for  notwithstanding  all  our 
strength  and  will,  the  area  of  the  bottom  of  the 
deep  sea  which  has  been  fairly  dredged  may  still 
be  reckoned  by  the  square  yard. 


FUOLO  "from    THF,   EASTERN    SHOUF,   OK    VIDKRO." 


C?TAP.  VI.] 


DEEP-SEA  DREDGING. 


281 


APPENDIX  A. 

One  of  the  Dredging  Papers  issued  hg  the  British  Assoeiatlon 
Committee,  filled  up  hj  Mr.  MacAndrein. 

DREDGING  PAPER  No.  5. 

Da^e.— 7th  of  June,  1849. 

LocaUty.—Off  Malta. 

Depth. — 40  fathoms. 

Distance  from  Shore.—l  to  2  miles. 

Ground.— ^ojid  and  stones, 

liegio7i.-~~ 


Srecies  obtained. 


Dentalium  dentalis    .... 
„  rubescens,  or  fissura 

„         tarentinum,  var.  (?) 


Caecum  trachea     .... 
Ditrupa  coarctata,  or  stranorti- 
lata ]    . 


Corbula  nucleus 

Nerora  cuspidata 

„       cost u lata     

Pandora  obtusa 

Psammobia  ferroensis  .  .  . 
Tellina  distorta 

„      balaustina 

„      serrata  

„      depressa 

Syndosmya  tenuis?  (prismatica?) 
Venus  ovata 


No.  of  living 
specimens. 

No.  of  dead 
sijecimene. 

Observations. 

Numerous. 

1 

(    Striated  with  an 

.1 

<       undulated    ap- 

.. 

.2 

(      pearance. 

Several. 

'2 

j  With   a    notched 

Several. 

1      apex. 

1  and  valves. 

1 

2  and  valves. 

1 

2 

Valves. 

i 

:j 

1  and  valves. 

1  and  valves. 

1 
1 

1  valve. 

• 

Valves. 

1 

Valves. 

282 


THE  DEPTHS  CF  THE  SEA. 


[chap.  VI. 


Species  obtained. 


Astarte  incrassata?     . 

Cardium  papillosum  . 
„  minimum  . 
,.  Itevigatum  , 
Cardita  squamosa .  . 
Lncina  spinifera  .  . 
Diplodonta  rotundata 
Modiola  barbata  .  . 
Nucula  micleus  .  , 
Leda  emarginata  .     . 

„  striata  .  .  . 
Area  tetragona . 

„     antiquata      .     . 
Pectunculus  glycimeris 
Lima  subauriculata    . 
Pecteii  jacobeeus    .     , 

„      gibbus    .     .     . 

„      polymorphus   . 

,,      testae.     .     .     . 

„      similis    .     .     . 

„  sulcatus  .  . 
Anomia  patelliformis 
Pileopsis  huugaricus  . 
Bulla  lignaria   .     .     . 

„      cranchii  .     .     . 

„      hydatis    .     .     . 

„  striatula  .  .  . 
Rissoa  bruguieri    .     . 

„      carinata  (costata^ 


acuta,  var.  . 
desmarestii 


Natica  macilenta  .     . 

Euliraa  polita   .     .     . 
,,      distorta     .     . 

Chemnitzia  varicosa  . 
„  elegantissima 

„  indistincta  (?) 


Eulimella  acicula  .     . 
Trochus  tenuis,  or  dubius 

„       magus.     .     . 

„       montaorui 


No.  of  livinj 
specimens. 


No.  of  dead 
specimens. 


Observations. 


Several. 
3 
4 

8 


i  Sulcated  to  the 
<  margin,  some  of 
(     them  radiated. 


Valve. 


1  valve. 


1  valve. 
1  and  valves. 
Valves. 
Valves. 
Valves. 
Valves. 

Viilves. 
1  and  valves. 

1 

1 
2 
4 
1 
3 


Several. 


Longer,  destitute 
of  ribs,  one 
very  large. 

\  Like    cimex,  but 
\      minute. 


Imperfect. 


■HAP.  VI.] 


DEEP-SEA  DREDGING . 


283 


Species  obtained. 


Trochus  montagui 

Turritella  terebra  .     . 
„         tricostalis  . 
Cerithum  vulgatuin,  var 
reticulatum 


Fusus  muricatus 


Pleurotoma  nanum     . 
„  secalinum 

Murex  tetrapterus  . 
Chenopus  pes-pelecani 
Buccinum  1 .  .  .  . 
Mitraebenea     .     .     . 


Ringicula  auriculata  . 
Marginella  secalina    . 

„  clandestina 

Cyprsea  pulex  .  .  . 
Cidaris  histrix  .  .  . 
Zoophytes  .... 
Algae  ...... 


No.  of  living 
specimens. 


Few. 
1 


3 

Several. 


No.  of  dead 
specimens. 


Several. 
Several. 


Several. 
2 


2 

4 

Several. 

2 


Observations. 


Small. 


White. 


This     species     at 
Gibraltar. 


(  Bright  orange 
<  colour,  banded, 
(     small,  striated 


CHAPTER  YLL 

DEEP-SEA   TEMPERATURES. 

Ocean  Currents  and  their  general  Effects  on  Climate.— Determination 
of  Surface  Temperatures.-  -Deep-sea  Thermometers.— The  ordinary 
Self-registering  Thermometer  on  Six's  principle. — The  Miller- 
Casella  modification. — The  Temperature  Observations  taken  during 
the  Three  Cruises  of  H.M.S.  '  Porcupine  '  in  the  year  1869, 

Appendix  A. — Surface  Temperatures  observed  on'  board  H.M.S. 
'Porcupine'  during  the  Summers  of  1869  and  1870. 

Appendix  B.— Temperature  of  the  Sea  at  different  Depths  near  the 
Eastern  Margin  of  the  North  Atlantic  Basin,  as  ascertained  by 
Serial  and  by  Bottom  Soundings. 

Appendix  C. — Comparative  Rates  of  Reduction  of  Temperature  with 
Increase  of  Depth  at  Three  Stations  in  different  Latitudes,  all  of 
them  on  the  Eastern  Margin  of  the  Atlantic  Basin. 

Appendix  D. — Temperature  of  the  Sea  at  different  Depths  in  the 
Warm  and  Cold  Areas  lying  between  the  North  of  Scotland, 
the  Shetland  Islands,  and  the  Faeroe  Islands ;  as  ascertained  by 
Serial  and  Bottom  Soundings. 

Appendix  E. — Intermediate  Bottom  Temperatures  showing  the  Inter- 
mixture of  Warm  and  Cold  Currents  on  the  Borders  of  the 
Warm  and  Cold  Areas. 

1^  the  surface  of  this  world  of  ours  were  one 
uniform  shell  of  dry  land,  other  circumstances  of 
its  central  heat,  its  relation  in  position  to  the  sun, 
and  to  its  investing  atmospheric  envelope,  remaining 
the  same,   some  zones  would  present  certain  pecu- 


CHAP.  VII.]  DEEP-SEA  TE.h'PEJtJTUnES.  285 

liarities  in  temperature,  owing  to  the  mixture  of 
hot  and  cold  currents  of  air;  hut  in  the  main,  iso- 
thermal lines,  that  is  to  say,  lines  drawn  tiirough 
places  having  the  same  mean  temperature,  would 
coincide  with  parallels  of  latitude.  A  glance  at  any 
isothermal  chart,  whether  for  the  whole  year,  for 
summer,  for  winter,  or  for  a  single  month,  will  show 
that  this  is  far  from  heing  the  case.  The  lines  of 
equal  temperature  deviate  everywhere,  and  often 
most  widely,  from  their  noi^mal  parallelism  with  the 
parallels  of  latitude  and  with  each  other.  A  glance 
at  the  same  chart  will  also  show,  that  wiiile  there 
is  an  attempt,  as  it  were,  on  the  part  of  the  iso- 
thermal lines  to  maintain  their  normal  direction 
through  the  centre  of  great  continents,  the  most 
marked  curves,  indicating  the  widest  extensions  of 
uniform  conditions  of  temperature,  are  where  there 
is  a  wide  stretch  of  open  sea  extending  through 
many  degrees  of  latitude,  and  consequently  includ- 
ing very  different  climatal  conditions. 

The  lands  bordering  upon  the  ocean  partake  in 
this  general  diffusion  of  heat  and  amelioration  of 
climate,  and  hence  we  have  the  difference  between 
continental  and  insular  climates — the  former  giving 
extremes  of  summer  heat  and  winter  cold,  and  the 
latter  a  much  more  uniform  temperature,  somewhat 
below  the  normal  temperature  within  the  tropics, 
and  usually  greatly  above  it  beyond  their  limits. 

The  islands  of  Ireland  and  Great  Britain  and  the 
west  coast  of  the  Scandinavian  peninsula  are  in- 
volved in  the  most  extreme  system  of  abnormal 
curves  which  we  have  in  any  of  the  ocean  basins  ; 
and  to  this  peculiarity  in  the  distribution  of  tern- 


286  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

perature  in  the  North  Atlantic  we  are  indebted  for 
the  singular  mildness  of  our  winter  climate.  The 
chart  PL  YII.,  the  general  result  reduced  from  many- 
hundreds  of  thousands  of  individual  observations, 
gives  the  distribution  of  the  lines  of  equal  mean 
temperature  for  the  surface  of  the  North  Atlantic 
for  the  month  of  July  ;  and  it  will  be  seen  that 
the  isotherms,  instead  of  passing  directly  across  the 
ocean,  form  a  series  of  loops  widening  and  flatten- 
ing northwards,  all  participating  in  certain  secondary 
deflections  which  give  them  a  scalloped  appearance, 
but  all  of  them  primarily  referred  to  some  common 
cause  of  the  distribution  of  heat,  having  its  origin 
somewhere  in  the  region  of  the  Straits  of  Elorida. 

These  peculiarities  in  the  distribution  of  tempera- 
ture on  the  surface  of,  the  sea  may  usually  be  very 
immediately  traced  to  the  movement  of  bodies  of 
water  to  and  from  regions  where  the  water  is  exposed 
to  different  climatal  conditions; — to  warm  or  cold 
ocean  currents,  which  make  themselves  manifest  like- 
wise by  their  transporting  power,  their  effect  in 
speeding  or  retarding  vessels,  or  diverting  them  from 
their  courses.  Prequently,  however,  the  current, 
although  possibly  involving  the  movement  of  a  vast 
mass  of  water,  and  exerting  a  powerful  influence 
upon  climate,  is  so  slow  as  to  be  imperceptible ;  its 
steady  onward  progress  being  continually  masked 
by  local  or  variable  currents,  or  by  the  drift  of  the 
prevailing  winds. 

The  Gulf-stream,  the  vast  'warm  river'  of  the 
North  Atlantic,  which  produces  the  most  remark- 
able and  valuable  deviations  of  the  isothermal  lines 
Avhich  we  meet  with  in  any  part  of  the  world,  is  in 


CHAP.  VII.]  DEEF-SEA  TEMFERATURES.  287 

this  way  imperceptible  by  any  direct  effect  upon 
navigation  beyond  the  45th  parallel  of  north  latitude, 
a  peculiarity  which  has  produced  and  still  produces 
great  misconceptions  as  to  its  real  character. 

The  mode  of  determining  the  surface  temperature 
of  the  ocean  is  sufficiently  simple.  A  bucket  is 
let  down  from  the  deck  of  the  vessel,  dashed  about 
for  a  little  in  the  water  to  equalize  the  temperature, 
and  filled  from  a  depth  of  a  foot  or  so  below  the  sur- 
face. The  temperature  of  the  water  in  the  bucket  is 
then  taken  by  an  ordinary  thermometer,  whose  error 
is  known.  A  common  thermometer  of  the  Kew 
Observatory  pattern  graduated  to  Pahrenheit  degrees 
can  be  read  with  a  little  practice  to  a  quarter  of  a 
degree,  and  a  good- sized  centigrade  thermometer  to 
a  tenth.  Observations  of  .surface- temperature  are 
usually  made  every  two  hours,  the  temperature  of 
the  air  being  taken  with  each  observation,  and  the 
latitude  and  longitude  noted  at  noon,  or  more  fre- 
quently by  dead  reckoning  if  required. 

Every  observation  of  the  surface-temperature  of 
the  sea  taken  accurately  and  accompanied  by  an 
equally  exact  note  of  the  date,  the  geographical 
position,  and  the  temperature  of  the  air,  is  of  value. 
The  surface  observations  taken  from  H.M.S.  '  Por- 
cupine' during  her  dredging  cruise,  in  the  summer 
of  1869,  are  given  in  Appendix  A. 

The  surface-temperature  of  the  North  Atlantic  has 
been  the  subject  of  almost  an  infinite  number  of  such 
observations,  more  or  less  accurate.  Dr.  Petermann, 
in  a  valuable  paper  on  the  northern  extension  of 
the  Gulf-stream,  reduces  the  means  of  more  than  a 
hundred  thousand  of  these,  and  deduces  the  scheme 


288  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

of  curves  which  has  been  used  with  some  slight 
modification  in   the  construction  of  this  chart. 

Until  very  recently  little  or  nothing  has  been 
known  with  any  certainty  about  the  temperature  of 
the  sea  at  depths  below  the  surface.  This  is,  however, 
a  field  of  inquiry  of  very  great  importance  in  Physical 
Geography,  as  an  accurate  determination  of  the  tem- 
perature at  different  depths  is  certainly  the  best, 
frequently  the  only  available  means  of  determining 
the  depth,  width,  direction,  and  generally  the  path  of 
the  warm  ocean  currents,  which  are  the  chief  agents 
in  the  diffusion  of  equatorial  heat ;  and  more  espe- 
cially of  those  deeper  indraughts  of  frigid  water 
which  return  to  supply  their  place  and  to  com- 
plete the  general  cycle  of  oceanic  circulation.  The 
main  cause  of  this  want  of  accurate  knowledge  of 
deep-sea  temperatures  is  undoubtedly  the  defective- 
ness of  the  instruments  which  have  been  hitherto 
employed. 

The  thermometer  which  has  been  almost  universally 
used  for  this  purpose  is  the  ordinary  self-registering 
thermometer  on  Six's  construction,  enclosed  in  a 
strong  copper  cise,  with  valves  or  apertures  below 
and  above  to  allow  a  free  current  of  water  to  pass 
through  the  case  and  over  the  surface  of  the 
instrument.  Six's  registering  thermometer  (Pig.  53) 
consists  of  a  glass  tube  bent  in  tlie  form  of  a  Y, 
one  limb  terminating  in  a  large  cylindrical  bulb, 
entirely  filled  with  a  mixtura  of  creosote  and  water. 
The  bend  of  the  tube  contains  a  column  of  mercury, 
and  the  other  limb  ends  in  a  small  bulb  partially 
filled  with  creosote  and  water,  but  Avitli  a  large 
space  empty,  or  rather  containing  the  vapour  of  the 


CHAP.  VII.]  DEEP-SEA .  TEMPERATURES.  289 

liquid  and  slightly  compressed  air.  A  small  steel 
index,  with  a  hair  tied  round  it  to  act  as  a  spring 
and  maintain  the  index  in  any  position  which  it 
may  assume,  lies  free  in  the  tuhe  among  the  creo- 
sote at  either  end  of  the  column  of  mercury.  This 
thermometer  gives  its  indications  solely  by  the  con- 
traction and  expansion  of  the  liquid  in  the  large  full 
bulb,  and  is  consequently  liable  to  some  slight  error 
from  the  effect  of  variations  of  temperature  upon 
the  liquids  in  other  parts  of  the  tube.  When  the 
liquid  in  the  large  bulb  expands,  the  column  of  mer- 
cury is  driven  upwards  towards  the  half-empty  bulb, 
and  the  limb  of  the  tube  in  which  it  rises  is  graduated 
from  below  upwards  for  increasing  heat.  When  the 
liquid  contracts  in  the  bulb,  the  column  of  mercury 
falls  in  this  limb,  but  rises  in  the  limb  terminating  in 
the  full  bulb,  which  is  graduated  from  above  down- 
wards. W^hen  the  thermometer  is  going  to  be  used  the 
steel  indices  are  drawn  down  in  each  limb  of  the  tube 
by  a  strong  magnet,  till  they  rest  on  each  side  on 
the  surface  of  the  mercury.  When  the  thermometer 
is  brought  up,  the  height  at  which  the  lower  end  of 
the  index  stands  in  each  tube  indicates  the  limit  to 
which  the  index  has  been  driven  by  the  mercury, 
the  extreme  of  heat  or  cold  to  which  the  instrument 
has  been  exposed. 

Unfortunately,  the  accuracy  of  the  ordinary  Six's 
thermometer  cannot  be  depended  upon  beyond  a 
very  limited  depth,  for  the  glass  of  the  bulb  which 
contains  the  expanding  fluid  yields  to  the  pressure 
of  the  water,  and,  compressing  the  contained  fluid, 
gives  an  indication  higher  than  is  due  to  tem- 
perature  alone.      This    cause    of    error   is   not   con- 

u 


290  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

stant  ill  its  action,  as  the  amount  to  which  the 
bulb  is  compressed  depends  upon  its  form  and  upon 
the  thickness  and  quality  of  the  glass ;  thus  the 
error  of  good  thermometers  of  the  Hydrographic 
Office  pattern  varies  from  7°  C.  to  10°-5  C.  at  a  pres- 
sure of  6*817  lbs.  on  the  square  inch,  representing 
a  depth  of  2,500  fathoms.  In  thoroughly  well- 
constructed  thermometers,  however,  such  as  those 
made  by  Casella  and  Pastorelli  for  the  English 
Admiralty,  the  pressure  error  is  tolerably  constant ; 
and  Captain  Davis,  R.N.,  who  has  lately  conducted 
important  experiments  on  this  point,  expresses  his 
opinion  that  by  an  extended  series  of  observations 
a  scale  might  be  obtained  to  correct  the  ther- 
mometers hitherto  in  use  to  a  close  approximation 
to  the  truth,  and  thus  utilize  to  some  extent  obser- 
vations which  have  been  already  made  with  our 
ordinary  instruments. 

In  the  'Lightning'  expedition  in  1868  we  used 
the  ordinary  Hydrographic  Office  pattern,  and  a 
large  number  by  different  makers  were  sent  with 
us  for  testing  and  comparison.  The  depths  not 
being  very  great,  the  general  temperature  results 
came  out  well,  and  were  among  the  most  singular 
phenomena  which  we  had  to  record.  Many  of  the  in- 
struments were  very  wild  at  a  few  hundred  fathoms, 
and  several  gave  way  under  the  pressure.  On  our 
return  in  April  1869,  Dr.  W.  A.  Miller,  V.P.U.S., 
attended  a  meeting  of  the  Deep-Sea  Committee  of 
the  lloyal  Society  at  the  Hydrographic  Office, 
and  proposed  encasing  the  full  bulb  in  an  outer 
covering  of  glass  containing  air,  in  order  to  permit 
the  air  to   be   compressed   by  the   pressure   of    the 


CHAP.  VII.] 


DEEP-SEJ  TEMPERATURES. 


291 


§60- 


water  on  the  outer   shell,  and   thus   protecting  the 
bulb  within. 

Mr.  Casella  was  directed  to  construct  some  ther- 
mometers on  this  plan,  only  instead  of 
being  filled  with  air,  the  outer  shell 
was  nearly  filled  with  alcohol  warmed 
to  expel  a  portion  of  the  remaining 
air,  and  the  chamber  Avas  then  her- 
metically sealed,  leaving  a  bell  of  air 
and  vapour  of  alcohol  to  yield  to  the 
pressure  and  relieve  the  bulb  within. 
The  '  Miller  -  Casella  '  thermometer 
proved  so  nearly  perfection  that  it  was 
decided  to  adopt  it  in  future,  and  to 
use  it  as  a  standard  in  a  series  of 
experiments  which  were  undertaken 
to  test  the  ordinary  Six's  thermo- 
meters of  the  Hydrographic  Office 
pattern.  We  depended  upon  this 
thermometer  alone  in  our  subsequent 
cruises  in  the  '  Porcupine,'  and  we 
found  it  most  satisfactory.  During  the 
summer  of  1869  temperature  observa- 
tions were  taken  at  upwards  of  ninety 
stations,  at  depths  varying  from  10  to 
2,435  fathoms.  Two  thermometers, 
numbered  100  and  103  respectively, 
were  sent  down  at  everv  station,  and 
in  no  instance  did  they  give  the  least 
reason  to  doubt  their  accuracy.  Every 
observation  was  taken  by  Captain  Calver  himself, 
the  lead  with  the  thermometers  attached  being  in 
every  single  instance   let    down    by   his   own  hand, 

u  2 


Fig.  53.— The  Miller- 
Casella  iiioditicatioii 
of  Six's  self-regi.s- 
tering  therinomcter. 
The  large  bulb  is 
double,  with  a  layer 
of  liquid  and  a  bell 
of  vaiiour  between 
the  shells,  to  relieve 
pressure. 


292 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VII. 


I 


and  I  have  always  regarded  it  as  a  remarkable 
evidence  of  my  friend's  care  and  skill  that  he 
landed  those  two  precious  instruments  at  the  end 
of  the  year  safe  back  at  Woolwich. 

Fig\  53  represents  the  latest  im- 
provements on  the  Miller- Casella 
modification  of  Six's  self-registering 
thermometer.  The  instrument  is  of 
small  size,  to  reduce  as  far  as  pos- 
sible the  friction  in  passing  through 
the  water.  The  tube  is  mounted  in 
ebonite,  to  avoid  the  expansion  of  a 
wooden  mounting  in  the  water,  by 
which  the  instrument  is  liable  to 
get  jammed  in  the  case.  The  scale 
is  of  white  porcelain,  graduated  to 
Fahrenheit  degrees;  the  large  bulb 
is  enclosed  in  an  outer  shell  three- 
fourths  filled  with  alcohol  and  her- 
metically sealed.  It  is  right  to 
mention  that  I  am  informed  by 
Sir   Edward  Sabine   that   the    ther- 

FiG.  5 1.  — Copper  case   for  ,  i      i  o  •         t    i  t» 

protecting   the   Miller-  momctcrs    uscd    bv    Sir    John    Koss 

Casella  thermometer.  The    ...... 

ends  of  the  case  above  and   m     hlS     ArctlC    VOVafiTe     lU    1818     WCrC 
below  are  perforated   to  e/      o 

topass^Sy through'"''  pfotcctcd  somcwhat  on  the  same 
principle,  and  that  a  thermometer 
for  resisting  pressure  was  constructed  under  the 
directions  of  the  late  Admiral  Fitzroy,  at  the 
suggestion  of  Mr.  Glaisher,  which  diff'ered  from 
tlie  Miller-Casella  pattern  in  little  else  than  the 
outer  shell  being  partially  filled  with  mercury 
instead  of  alcohol,  and  in  being  somewhat  less 
compact   and  more   fragile   than   the   latter   instru- 


CHAP.  VII.]  DEEP-SEA  TEMPERATURES.  293 

ment/  A  modification  of  Phillip*s  maximum  ther- 
mometer devised  by  Sir  William  Thomson,  in  which 
the  thermometer  is  entirely  encased  in  an  outer 
shell  of  glass  partly  filled  with  alcohol,  appears  to 
have  the  smallest  error  of  all. 

A  neat  modification  of  Breguet's  metallic  ther- 
mometer was  designed  by  Joseph  Saxton,  Esq.,  of 
the  U.S.  Office  of  Weights  and  Measures,  for  the 
use  of  the  U.S.  Coast  Survey.  A  riband  of 
platinum  and  one  of  silver  are  soldered  with  silver 
solder  to  an  intermediate  plate  of  gold,  and  the 
compound  riband  is  coiled  round  a  central  axis  of 
brass,  with  the  silver  within.  Silver  is  the  most 
expansible  of  the  metals  under  the  influence  of 
heat,  and  platinum  nearly  the  least.  Gold  holds  an 
intermediate  place,  and  its  intervention  between  the 
platinum  and  silver  moderates  the  strain,  and  pre- 
vents the  coil  from  cracking.  The  lower  end  of 
the  coil  is  fixed  to  the  brazen  axis,  while  the  upper 

1  In  Messrs.  Negretti  and  Zambia's  list  of  meteorological  instruments 
published  in  1864,  a  deep-sea  thermometer  on  this  j)lan  is  mentioned 
(p.  90) :  "  The  thermometers  constructed  for  this  purpose  do  not  differ 
materially  from  those  usually  made  under  the  denomination  of  Six's 
thermometers,  except  in  the  following  most  important  particulars  : — 
The  usual  Six's  thermometers  have  a  central  reservoir  or  cylinder 
containing  alcohol ;  this  reservoir,  which  is  the  only  portion  of  the 
instrument  likely  to  be  affected  by  pressure,  has  been,  in  Negretti  and 
Zambra's  new  instrument,  superseded  by  a  strong  outer  cylinder  of 
glass,  containing  mercury  and  rarefied  air.  By  this  means  the  portion 
of  the  instrument  susceptible  of  compression  has  been  so  strengthened, 
that  no  amount  of  pressure  can  possibly  make  the  instrument  vary." 
Some  obscurity  is  introduced  into  this  passage  by  the  use  of  the  word 
'superseded;'  but  I  am  assured  by  Messrs.  Xegretti  and  Zambra  that 
in  principle  this  instrument  was  exactly  the  same  as  that  devised  by 
Professor  Miller  and  constructed  by  Mr.  Casella. 


294  THE  DEPTHS  OF  THE  SEJ.  [chap.  vii. 

end  is  attached  to  the  base  of  a  short  cylinder. 
Any  variation  of  temperature  causes  the  coil  to 
wind  or  unwind,  and  its  motion  acts  to  rotate  the 
axial  stem.  This  motion  is  magnified  by  multiply- 
ing wheels,  and  is  registered  upon  the  dial  of  the 
instrument  by  an  index  which  pushes  before  it  a 
registering  hand,  moving  with  sutficient  friction 
merely  to  retain  its  place  when  thrust  forward  by 
the  index  hand  of  the  thermometer.  The  instru- 
ment is  graduated  by  trial.  The  brass  and  silver 
2)ortions  are  thickly  gilt  by  the  electrotype  process 
to  prevent  the  action  of  sea-water  upon  them.  The 
box  which  covers  the  coil  and  indicatory  part  of  the 
thermometer  is  merely  to  protect  it  from  accidental 
injury,  and  is  open  so  as  to  permit  the  free  passage 
of  the  sea- water.  This  instrument  appears  to  answer 
tolerably  well  for  moderate  depths,  its  error  up  to 
600  fathoms  not  greatly  exceeding  0°'5  C. ;  at  1,500 
fathoms,  however,  the  error  rises  to  5°C.,  quite  as 
great  as  that  of  the  unprotected  Six's  thermometers, 
and  the  error  is  not  so  constant.  It  is  evident 
that  under  great  pressure  little  confidence  can  be 
placed  upon  instruments  which  give  their  indica- 
tions through  metal  machinery. 

Before  H.M.S.  '  Porcupine  '  started  on  her  summer 
cruise  in  1869,  a  valuable  series  of  experiments  were 
made  upon  the  effect  of  pressure  on  various  register- 
ing thermometers  at  Woolwich,  under  the  superin- 
tendence of  the  Hydrographer  and  of  the  Deep-Sea 
CJommittee  of  the  Rojal  Society.  The  object  was  to 
subject  all  the  forms  of  deep-sea  thermometers  in  use 
to  pressures  in  a  hydraulic  press,  equivalent  to  the 
pressures  which  they   would   encounter  at    different 


CHAP,  VII.J 


DEEP-SEA  TEMPERATURES. 


295 


depths  in  the  ocean,  to  determine  the  amount  and 
sources  of  error,  to  ascertain  which  was  the  most 
satisfactory  instrument,  and  if  possible  to  construct 
a  scale  by  which  the  observations  hitherto  taken 
with  ordinary  instruments  might  be  roughly  cor- 
rected, so  as  to  be  made  available.  As  there  was 
some  difficulty  in  getting  the  use  of  a  suitable  press, 
Mr.  Casella  undertook  to  have  a  testing  apparatus 
constructed  at  his  own  place  in  Hatton  Garden, 
capable  of  producing  a  pressure  of  three  tons  on 
the  square  inch. 

The  results  were  very  interesting.^  The  first  expe- 
riment went  to  test  the  value  of  the  various  instru- 
ments. A  Miller- Casella  thermometer  was  placed  in 
the  cylinder  with  No.  57,  a  good  thermometer  by 
Casella,  of  the  ordinary  Hydrographic  Office  pattern, 
and  they  were  subjected  together  to  a  pressure  of 
4,032  lbs.,  equal  to  1,480  fathoms,  with  the  following 
result  : — 


Thennometer. 

Minimum. 

Maximum. 

Difference  of 
Maximum. 

Before. 

After. 

Before. 

After. 

2 
57 

8-  6  C. 
8-  6 

8^-  6  C. 
8-6 

8°-  6  C. 
8-  6 

8°'85C.       0°-25C. 

12-75           4-15 

1 

That  is  to  say,  the  temperature  remaining  the  same, 
the  pressure  forced  up  No.  57  to  12°-75  C,  and  left  its 
index  there. 

1  On  Deep  Sea  Thermometers,  by  Captain  J.  E.  Davis,  R.N.  Nature^ 
vol.  iii.  p.  124.  Abridged  from  a  Paper  read  before  the  Meteorolo- 
gical Society,  April  19th,  1871. 


296 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VII. 


This  experiment  at  once  proved  the  advantage  of 
the  encased  bulb.  It  was  repeated  with  other  ther- 
mometers with  the  same  pressure  and  for  the  same 
period  of  time,  and  it  was  found  that  while  the  mean 
difference  of  the  encased  bulbs  was  only  0°-955  that  of 
the  ordinary  deep-sea  thermometers  was,  as  in  No.  57, 
7°*25.  It  foUow^s,  also,  from  these  experiments,  that 
very  nearly  all  the  difference  or  error  is  due  to  pres- 
sure on  the  full  bulb,  and  that  by  encasing  that  bulb 
we  have  a  nearly  perfect  instrument. 

The  next  series  of  experiments  was  made  to  esta- 
blish a  scale  by  which  observations  by  the  ordinary 
instruments  might  be  approximately  corrected  for 
pressure.  The  following  table  gives  the  errors  of 
six  thermometers  at  diflPerent  pressures.  The 
'  standard '  is  an  encased  Miller-Casella,  the  last 
a  registering  minimum  thermometer  by  Casella 
enclosed  in  a  hermetically  sealed  glass  tube  on  Sir 
William  Thomson's  plan. 


I 


Pressure 

in 

standard. 

No.  54. 

No.  56. 

No.  76. 

No.  73. 

Thomson. 

Fathoms. 

250 

0^-  4  C. 

0°-  8  C. 

1°-  0  c. 

0°-  7  C. 

0°-  8  C. 

0°-  0  G. 

500 

0-4 

1-7 

1  -5 

1  -4 

1  -7 

0-05 

750 

0-7 

2-2 

2-2 

2-  3 

2-5 

0-0 

1,000 

0-8 

2-9 

2-9 

2-  7 

2-7 

0-2 

1,250 

0-9 

3-5 

3-5 

3-5 

4-  1 

0-05 

1,500 

0-8 

4-3 

4-3 

4-  0 

4-3 

0-3 

1,750 

0-95 

4-  6 

4-9 

4-  7 

5-  7 

0-2 

2,000 

1  •  1 

5-  4 

5  •  5 

5-3 

6-4 

0-3 

2,250 

1  •  1 

6-  2 

6-0 

6-0 

6-  8 

0-4 

2,500 

1  -2 

7    2 

6-7 

6-5 

7-6 

0-2 

The  mean  diflPerence  for  each  250  fathoms  in  each 
thermometer  is  as  follows  : — 


CHAP.  VII.] 


DEEP-SEA  lEMPERATUBES. 


297 


Thermometer. 

Difference. 

Standard 

+   0"^-12C. 

54 

-f  0-72 

56 

+  0-67 

76 

+   0-65 

73 

+   0-76 

Thomson 

-f   0-03 

During  these  experiments  the  water  in  the  cylin- 
der was  of  course  maintained  as  far  as  possible  at 
the  same — or  at  a  known  temperature ;  a  certain 
amount  of  calorific  effect  must,  however,  be  pro- 
duced hj  the  sudden  compression  of  the  water,  and 
the  next  series  of  experiments  was  performed  in 
order  to  determine  the  amount  of  that  efPect.  Three 
of  Phillips's  encased  maximum  thermometers  (Sir 
William  Thomson's  design),  being  entirely  protected 
from  any  eflPect  from  compression,  were  employed  for 
this  purpose,  with  the  following  result : — 

Pressure,  6,817  lbs.  =  2,500  fathoms. 


Thennometer. 

Difference. 

11,424 

9,649 

9,645 

+   0=-  05  C. 
+  0-22 
+  0-11 

So  that  this  source  of  error  is  absolutely  trifling. 

The  true  error  of  the  Miller-Casella  thermometer, 
as  deduced  from  these  observations,  is — 

For  250  fathoms  0°'079  C. 
For  2,500  fathoms  0°-79  C. 


298 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VII. 


This,  therefore,  may  be  regarded  as  a  perfect  instru- 
ment for  all  ordinary  purposes. 

A  number  of  the  instruments  which  had  been 
previously  tested  in  the  press  were  sent  out  in  the 
'Porcupine'  on  her  summer  cruise  in  1869,  and  on 
her  return  the  results  of  Captain  Calver's  observa- 
tions at  different  depths  in  the  ocean  were  carefully 
compared  with  the  eflPects  of  equivalent  pressures  ap- 
plied to  the  thermometers  in  Mr.  Casella's  '  Bramah's 
press.'  The  result  in  the  ocean,  contrary  to  that  in 
the  hydraulic  press,  proves  that  the  elasticity  is  not 
regular  or  in  a  ratio  to  the  pressure,  but  that  after 
continuing  regular  up  to  a  pressure  of  1,000  fathoms, 
it  decreases  in  a  compound  ratio  to  a  pressure  of 
2.000  fathoms,  when  its  elasticity  nearly  ceases. 

The  following  table  gives  an  abstract  of  the 
behaviour  of  Casella's  ordinary  Hydrographic  Office 
thermometers  in  the  ocean  and  in  the  press : — 


Error. 

Per  250TATHOMS. 

Press. 

Ocean. 

Press, 

Ocean. 

Fathoms. 

i 

250 

0°-  726  C. 

0°-  738  C. 

0°-  726  C. 

0°-  738  C. 

500 

1  •  548 

1  -564 

0-  774 

0-782        1 

750 

2-  123 

2  •  223 

0-  708 

0-741        ' 

1,000 

2-  474 

3  -015 

0-674 

0-754 

1,250 

3-255 

3-492 

0  •  651 

0-  698 

1,500 

4-  107 

3-921 

0-  684 

0  •  653 

1,750 

4  •  555 

4-056 

0-650 

0-  579 

2,000 

5-354 

4-  284 

0-669 

0  -  536 

2,250 

6-021 



0-  669 



2,500 

1 

6-  817 

— 

0-  682 

— 

Por  taking  bottom  temperatures  at   great  depths 
two  or  more  of  the  Miller-Casella  thermometers  are 


CHAP.  VII.]  DEKP-SKi  TEMPERATURES.  299 

lashed  to  the  sounding-line  at  a  little  distance  from 
one  another,  a  few  feet  above  the  attaching  ring  of 
a  '  detaching '  sounding  instrument.  The  lead  is 
run  down  rapidly,  and,  after  the  weight  has  been 
disengaged  by  contact  with  the  ground,  an  interval 
of  five  or  ten  minutes  is  allowed  to  elapse  before 
hauling  in.  The  shorter  of  these  periods  seems  to 
be  quite  sufficient  to  insure  the  instrument  acquiring 
the  true  temperature.  In  taking  serial  temperature 
soundings — that  is  to  say,  in  determining  the  tem- 
perature at  certain  intervals  of  depth  in  deep  water 
— the  thermometers  are  attached  above  an  ordinary 
deep-sea  lead,  the  required  quantity  of  line  for  each 
observation  of  the  series  run  out,  and  the  ther- 
mometers and  lead  are  hove  in  each  time.  This  is 
a  very  tedious  process ;  one  serial  sounding  in  the 
Bay  of  Biscay,  where  the  depth  was  850  fathoms 
and  the  temperature  was  taken  at  every  fifty 
fathoms,   occupied  a  whole  day. 

I  ought  to  mention  that  in  taking  the  bottom 
temperature  with  the  Six's  thermometer  the  instru- 
ment simply  indicates  the  lowest  temperature  to 
which  it  has  been  subjected;  so  that  if  the  bottom 
water  were  warmer  than  any  other  stratum  through 
which  the  thermometer  had  passed,  the  observation 
would  be  erroneous.  This  is  only  to  be  tested  by 
serial  soundings,  but  in  every  locality  where  the 
temperature  was  observed  during  the  '  Porcupine ' 
expeditions  the  temperature  gradually  sank,  some- 
times very  steadily,  sometimes  irregularly,  from  the 
surface  to  the  bottom,  the  bottom  water  having  been 
constantly  the  coldest.  It  is  probable  that  under 
certain  conditions  in  the  Polar  seas,  where  the  sur- 


300  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

face  is  sometimes  subjected  to  intense  cold,  warmer 
water  may  be  found  below,  until  the  balance  is 
restored  by  convection.  This  I  believe,  however,  to 
be  entirely"  exceptional ;  and  it  may  certainly  be 
taken  as  the  rule  for  all  latitudes  that  if  we  dis- 
regard the  film  which  is  affected  by  diurnal  altera- 
tions, the  temperature  sinks  from  the  surface  to  the 
bottom. 

The  first  important  series  of  deep-water  tempera- 
ture observations  was  made  during  the  Arctic  voyage  ; 
under  Sir  John  Eoss  in  the  year  1818.  On  Sept.  the 
1st,  lat.  73°  37'  N.,  long.  77°  25'  W.,  the  temperature  \ 
at  the  surface  being  l°-3  C,  the  registering  thermo- 
meter gave  at  eighty  fathoms  0°  C,  and  at  250 
fathoms  —  V'4l  C.  On  the  6th  of  September,  lat. 
72°  23'  N.,  long.  73°  07'  W.,  the  first  serial  sounding 
on  record  was  taken,  the  thermometer  having  been  let 
down  to  500,  600,  700,  800,  and  1,000  fathoms  in 
succession,  the  thermometer  showing  each  time  a 
lower  temperature  and  indicating  at  the  greatest 
depth  named  a  temperature  of  —  3°-6  C.  On  the 
19th  of  September,  in  lat.  m""  50'  N.,  long.  60°  30' 
W.,  another  serial  sounding  was  taken,  the  tempera- 
ture being  registered  at  100  fathoms  —  0°*9  C,  at 
200  -l°-7  C,  at  400  -2°-2  C,  and  at  660  fathoms 
-3°-6  C.  On  the  4th  of  October,  lat.  61°  41'  N., 
long.  62°  16'  W.,  Sir  John  Eoss  sounded,  but  found 
no  ground  in  950  fathoms ;  at  the  same  time  the 
self-registering  thermometer  was  sent  down,  and  the 
temperature  of  the  sea  at  that  depth  was  found  to 
be  2°  C,  while  at  the  surface  it  was  4°  C,  and  the  air* 
at  2°-7  0.  I  am  informed  by  General  Sir  Edward 
Sabine,  who  accompanied  Sir  John  Uoss's  expedition. 


I 


HAP.  VII.}  DEEP-SEA  TEMPERATURES.  301 

that  these  observations  were  made  with  registering 
thermometers  guarded  somewhat  in  the  same  way 
as  those  which  we  employed  in  the  '  Porcupine.' 
There  is  almost  sufficient  internal  evidence  that  the 
mode  of  protecting  these  thermometers  must  have 
been  satisfactory,  for  the  temperatures  at  the  greatest 
depths  are  such  as  might  have  been  expected  from 
Miller-Casella  thermometers.  Unguarded  instru- 
ments would  certainly  have  given  higher  indica- 
tions. 

The  last  of  the  observations  quoted,  a  considerable 
way  up  Davis'  Strait,  is  of  great  interest.  The  tem- 
perature of  the  surface  of  the  sea  was  nearly  a 
degree  and  a  half  Centigrade  above  that  of  the  air, 
and  the  temperature  of  the  water  was  altogether 
unusually  high.  It  is  now  well  known  that  at 
certain  seasons  of  the  year  a  very  marked  extension 
of  the  Gulf-stream  passes  into  the  mouth  of  the 
Strait.  The  isotherms  for  September  and  July  are 
shown  on  the  chart  from  data  kindly  procured  for 
me  by  Mr.  Keith  Johnston. 

Sir  Edward  Sabine,  in  an  extract  from  his  pri- 
vate Journal  of  Sir  John  Ross's  voyage  quoted  by 
Dr.  Carpenter,^  gives  a  lower  temperature  than  any 
hitherto  recorded.  He  says  :  "  Having  sounded  on 
September  19th,  1818,  in  750  fathoms,  the  regis- 
tering thermometer  was  sent  down  to  680  fathoms, 
and  on  coming  up  the  index  of  greatest  cold  was 
at  25°*75  Eahrenheit  (  — 3°'5  C),  never  having  known 
it  lower  than  28°  (  — 2°-2  C.)  in  former  instances,  even 
at  a  depth  of  1,000   fathoms;    and  at   other  times 

1  Dr.  Carpenter's  Preliminary  Eeport  on  Deep- Sea  Dredgings.  Pro- 
ceedings of  the  Royal  Society  of  London,  vol.  xvii.  p.  186. 


302  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

when  close  to  the  bottom,  I  was  very  careful  in 
examining  the  thermometer,  but  could  discover  no 
other  reason  for  it  than  the  actual  coldness  of  the 
water." 

Notwithstanding  these  observations  and  several 
others  telling  in  the  same  direction, — such  as  those 
of  Lieutenant  Lee  of  the  U.S.  Coast  Survey,  who 
in  August  1847  found  a  temperature  of  2°- 7  C.  below 
the  Gulf-stream,  at  the  depth  of  1,000  fathoms, 
in  lat.  35°  26' N.,  and  long.  73°  12' W. ;  and  of 
Lieutenant  Dayman,  who  found  the  temperature 
at  1,000  fathoms,  in  lat.  51°  N.  and  long.  40°  W. 
to  be  0°*4C.,  the  surface  temperature  being  12°'5  C, 
the  impression  seems  to  have  prevailed  among 
physicists  and  physical  geographers  that  salt  water 
followed  the  same  law  as  fresh  water,  attaining  its 
greatest  density  at  a  temperature  of  4°  C.  The 
necessary  result  of  this  condition,  were  it  to  exist, 
is  thus  stated  by  Sir  John  Herschel :  ''In  very 
deep  water  all  over  the  globe  a  uniform  temperature 
of  39°  Eahrenheit  (4°C.)  is  found  to  prevail;  while 
above  the  level  where  that  temperature  is  first 
reached,  the  ocean  may  be  considered  as  divided 
into  three  great  regions  or  zones — an  equatorial  and 
two  polar.  In  the  former  of  these  warmer,  and  in 
the  latter  colder  water  is  found  on  the  surface.  The 
lines  of  demarkation  are  of  course  the  two  isotherms 
of  39°  mean  annual  temperature.''  Dr.  Wallich 
gives  an  excellent  resume  of  this  curious  fallacy. 
He  says  :  "  But  whilst  the  temperature  of  the  atmo- 
sphere beyond  the  line  of  perpetual  congelation  goes 
on  gradually  increasing,  that  of  the  water  below  the 
isothermal   line    remains    constant    to    the   bottom. 


CHAP.  VII.]  DEEP-SEA  TEMPERATURES.  303 

Were  it  not  for  the  operation  of  the  law  on  which 
the  latter  phenomenon  depends,  the  entire  ocean 
would  long  since  have  hecome  solidified,  and  both 
sea  and  land  rendered  unfit  for  the  habitation  of 
living  organisms.  Unlike  other  bodies  which  ex- 
pand and  become  lighter  with  every  rise  in  tempera- 
ture, water  attains  its  maximum  density,  not  under 
the  lowest  degree  of  cold,  but  at  39°- 5  Fahrenheit; 
and  consequently  so  soon  as  the  superficial  layer 
of  sea  is  cooled  down  to  this  degree,  it  descends, 
and  allows  a  fresh  portion  to  ascend  and  be  in 
turn  cooled.  This  process  is  continued  until  the 
whole  upper  stratum  is  reduced  in  temperature  to 
39°*5,  when,  instead  of  contracting  further,  it  begins 
to  expand  and  get  lighter  than  the  water  beneath, 
floats  on  it,  becomes  further  cooled  down,  and  at 
28°'5  is  converted  into  ice.  .  .  .  Thus  under  the 
operation  of  an  apparently  exceptional  law,  the 
equilibrium  of  the  oceanic  circulation  is  maintained  ; 
for  whilst  at  the  equator  the  mean  temperature  of 
the  surface  layer  of  water,  which  is  82°,  gradually 
decreases,  until  at  a  depth  of  1,200  fathoms  it  be- 
comes stationary  at  39° '5,  and  retains  that  tempera- 
ture to  the  bottom,  within  the  Polar  regions  and 
extending  to  lat.  56°  25'  in  either  hemisphere,  the 
temperature  increases  from  the  surface  downwards 
to  the  isothermal  line,  beyond  which  it  remains 
uniform  as  in  the  former  case.  Hence  in  lat.  56°  25' 
the  temperature  is  uniform  the  wiiole  way  from  the 
surface  to  the  bottom;  and  as  has  been  found  by 
observation  about  lat.  70°,  the  isothermal  line  occurs 
at  750  fatiioms  below  the  surface."  ^ 

1  Dr.  Wallich  :  JSTorth  Atlantic  Sea-bed,  p.  99. 


304  THE  DEPTUS  OF  THE  SEA.  [chap.  vii.   \ 

There  can  be  no  doubt  that  this  view,  which  of 
late  years  has  received  almost  universal  acceptance, 
is  entirely  erroneous.  It  has  been  shown  by  M. 
Despretz,'  as  the  result  of  a  series  of  carefully  con- 
ducted experiments  which  have  since  been  frequently 
repeated  and  verified,  that  sea-water,  as  a  saline 
solution,  contracts  and  increases  steadily  in  density 
down  to  its  freezing-point,  which  is,  when  kept 
perfectly  still,  about  ~3°-67  G.  (25°-4P.),  and  when 
agitated  -2°-55  C. 

The  temperature  observations  of  Sir  James  Clarke 
Ross  during  his  Antarctic  voyage  in  1840-41, 
seemed  to  give  support  to  the  theory  of  a  constant 
temperature  of  4°'5  C.  for  deep  water,  but  these  obser- 
vations have  as  evidently  been  made  with  unguarded 
instruments,  as  those  of  Sir  John  Ross  in  1818  with 
instruments  defended  from  pressure;  and  although 
I  believe  they  must  be  taken  as  proving  that  in 
high  southern  latitudes  the  surface  temperature  is 
sometimes  lower  than  the  temperature  of  the  water 
at  a  considerable  depth  beneath,  still  the  amount  of 
correction  for  pressure  is  uncertain,  depending  upon 
the  construction  of  the  thermometers  used,  and  in 
any  case  it  must  reduce  the  difference  considerably. 

A  large  number  of  thermometers  of  the  ordinary 
Hydrographic  Office  pattern  were  sent  out  with  us, 
as  I  have  already  mentioned,  in  the  *  Lightning,' 
and  these  were  of  course  the  instruments  used  by 
Staff-Commander  May  for  his  temperature  obser- 
vations. There  was  an  opportunity  of  testing  these 
thermometers,  however,  on  the  return  of  the  vessel, 

Recherches  sur  le  Maximum  de  Densite  des  Dissolutions  aqueuses. 
Loc.  cit. 


I    CHAP.  VII.]  DEEP-SEA  TEMPERATURES.  305 

SO  that  we  are  tolerably  certain  by  actual  experi- 
ment of  the  amount  of  their  error.  In  speaking 
of  the  '  Ijightning  '  temperatures,  I  mean,  therefore, 
the  actual  temperatures  taken  by  the  ordinary  ther- 
mometers, corrected -approximately  to  tlie  standard 
of  the  Miller-Casella  thermometers,  afterwards  used 
in  the  '  Porcupine.' 

Leaving   Stornoway   in   the   '  Lightning/    on    the 
11th   of  August,    1868,    and    directing    our    course 
towards  the  Fseroe  banks,  we  sounded  in  500  fathoms 
about    60    miles    to    the    north-west    of    the    Butt 
I  of   the   Lews,   and   took   a   bottom    temperature   of 
9°*4   Cent,  with    the  ordinary    Six's   thermometer — 
the  only  form  of  the  instrument  in  use  at  the  time. 
This,  when  corrected  for  pressure,  gives  about  7°8  C. 
We  were  surprised  to  find  the  temperature  so  high, 
I  and  we  were  at  the  time  inclined  to  think  that  the 
I  observation,  which  was  taken  in  a  breeze  of  wind, 
I  was   scarcely   to    be    depended    upon.      Subsequent 
observations,   however,    in    the    same   locality,    con- 
'  firmed  its    accuracy.      On    the   Pgeroe    Banks,  at  a 
I  depth  under  100  fathoms,   the   bottom   temperature 
I  averaged  9°  C,  while  that  of  the  surface  was  about 
I  12''  C.  ;  temperature  indications  on  this  bank  were, 
j  however,  of  little  value,    as  the  water   is  no  doubt 
'  affected  to  some  extent  through  its  entire  depth  by 
direct   solar   radiation.      Tlie   next   observation   was 
in  lat.  60°  45'  N.  and  long.  4°  49'   W.,  at  a  depth 
of    510    fathoms,    with    a    bottom    temperature   of 
—  0°'5  C,    about    140    miles    nearly    directly    north 
of   Cape  AVrath.     Then  followed  a  series  of  sound- 
ings, Nos.  7,  8,  10,  and  11  of  the  chart   (Plate   L), 
taken  while  traversing  the  northern  portion  of  the 

X 


306  THE  DEPTHS  OF  THE  SEA.  [chap.  vu. 

channel  between  Scotland  and  the  Eaeroe  plateau ; 
and  giving,  respectively,  the  temperatures  of  — 1°-1, 
-r-2,  -0°-7,  and  -0°-5C.  No.  9,  with  a  depth  of 
170  fathoms*  and  a  temperature  of  5°  C,  is  excep- 
tional; it  is  apparently  the  top  of  a  circumscribed 
ridge  or  bank.  We  dredged  at  this  station  and  got 
large  numbers  of  the  rare  and  beautiful  Terehratula 
cranium, ;  but  when  we  tried  for  the  same  spot  in  the 
following  year  in  the  '  Porcupine,'  we  could  not  find 
it.  On  the  6th  of  September  w^e  sounded  and  took 
temperatures  in  lat.  59°  36'  N.,  long.  T  20'  W.,  in 
530  fathoms,  when  the  mean  of  three  thermometers, 
which  only  differed  from  one  another  by  about  *3 
of  a  degree,  gave  a  bottom  temperature  of  6° '4  C. 
A  temperature  sounding,  at  the  moderate  depth  of 
189  fathoms,  was  taken  on  the  morning  of  the  7th 
September  in  lat.  59°  5'  N.,  long.  T  29'  W.,  and 
gave  a  bottom  temperature  of  9°'6  C.  The  three 
soundings,  Nos.  13,  14,  and  17,  at  the  depths  650, 
570,  and  620  fathoms,  extending  into  the  North 
Atlantic  as  far  westward  as  long.  12°  36'  W.,  gave 
a  bottom  temperature  of  5°*8,  6°'4,  and  6°'6  C, 
respectively. 

The  general  result  of  these  observations  we  could 
not  but  regard  as  very  remarkable.  The  region 
which  we  had  somewhat  imperfectly  examined  in- 
cluded, in  the  first  place,  the  channel  about  a  couple 
of  hundred  miles  in  width,  with  an  extreme  depth 
of  rather  under  600  fathoms,  extending  between  the 
northern  boundary-line  of  the  British  plateau  and 
tlie  shoal  which  culminates  in  the  Pgeroe  Islands 
and  their  extensive  banks;  and  secondly,  a  small  I 
portion  of  the  North  Atlantic  extending  Avestwardsj 


CHAP.  VII.]  DEEP-SEA  TEMPERJTURES.  307 

and  northwards  of  the  western  entrance  of  the  channel. 
We  found  that  in  these  two  areas,  freely  communi- 
cating with  one  another  and  in  immediate  proximity, 
two  totally  different  conditions  of  climate  existed  at 
all  depths  below  the  immediate  surface,  where  they 
differed  but  slightly.  In  the  Pseroe  channel,  at  a 
depth  of  500  fathoms,  the  bottom  temperature  aver- 
aged — 1°0  C,  while  at  a  like  depth  in  the  Atlantic 
the  minimum  index  stood  at  +6°  C,  a  difference  of 
7  degrees  Centigrade,  nearly  13  degrees  Eahrenheit. 

The  conclusion  at  which  we  speedily  arrived  as 
the  only  feasible  explanation  of  these  phenomena 
was  that  an  arctic  stream  of  frigid  water  crept  from 
the  north-eastward  into  the  Fseroe  channel  lying  in 
the  deeper  part  of  the  trough,  owing  to  its  higher 
specific  gravity  ;  while  a  body  of  water  warmed  even 
above  the  normal  temperature  of  the  latitude,  and 
therefore  coming  from  some  southern  source,  was 
passing  northwards  across  its  western  entrance  and 
occupying  the  whole  depth  of  that  comparatively 
shallow  portion  of  the  Atlantic  from  the  surface  to 
the  bottom. 

Several  important  facts  of  very  general  applica- 
tion in  Physical  Geography  had  been  placed  beyond 
doubt  by  these  observations.  It  had  been  shown 
that  in  nature,  as  in  the  experiments  of  M.  Despretz, 
sea-water  does  not  share  in  the  peculiarities  of  fresh 
water,  which,  as  has  been  long  known,  attains  its 
maximum  density  at  4°  C. ;  but,  like  most  other 
liquids,  increases  in  density  to  its  freezing-point :  and 
it  had  also  been  shown  that,  owing  to  the  movement 
of  great  bodies  of  water  at  different  temperatures 
in  different  directions,  we  may  have  in  close  proxi- 

x  2 


308  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

mity  two  ocean  areas  with  totally  different  bottom 
climates — a  fact  wliich,  taken  along  with  the  dis- 
covery of  abundant  animal  life  at  all  depths,  has 
most  important  bearings  upon  the  distribution  of 
marine  life,  and  upon  the  interpretation  of  pah^eon to- 
logical  data. 

The  conditions  during  the  '  Lightning '  cruise  were 
so  unfavourable  to  careful  observation,  that  we  deter- 
mined to  take  the  earliest  opportunity  of  going  over 
this  region  again,  and  determining  the  limits  of  these 
warm  and  cold  areas,  and  investigating  their  con- 
ditions more  in  detail.  Accordingly,  in  the  follow-  ^ 
ing  year,  when  we  had  H.M.S.  'Porcupine'  at  our  ' 
disposal.  Dr.  Carpenter  and  I  once  more  left  Storno- 
way  on  the  15th  of  August,  1869.  On  this  occasion 
we  had  everything  in  our  favour;  the  w^eather  w^as 
beautiful,  the  vessel  suitable,  and  we  were  provided 
with  Miller- Casella  thermometers  on  whose  accuracy 
we  could  depend.  A  table  of  Captain  Calver's  valu- 
able thermometrical  observations  during  this  cruise 
is  given  in  Appendix  A  to  this  chapter. 

We  proceeded  to  very  nearly  the  same  spot  when 
we  had  taken  our  first  sounding  on  the  former  year,] 
and  took  a  warm  area  temperature  of  7°*7  C.  Statioi 
No.   46   (Plate  IV.).      We   then    moved   on   slowly' 
towards   the  Paeroe  fishing  banks,  finding  in  succes- 
sion at  Stations  47,  49,  and  50,  -  6°-5,  T'Q,  and  7°'9  C.j 
At  Station  51,  about  40  miles   south  of  the  bank,} 
there  was  a  decided  fall  of  temperature — the   ther- 
mometer indicating  5°'6  C.  at  a  depth  of  440  fathoms  ;j 
and  about  20  miles  directly  northwards  a  soundin' 
at  Station  52,  lat.  60°  25'  N.,  long.  8°  10'  W.,  at 
depth  of  only  380  fathoms,  gave  a  minimum  tern- 


CHAP.  VII. J  DEEP-SEA  TE3IPERATURES.  309 

perature  of  —  0°'8  C,  showing  that  we  had  passed 
the  boundary,  and  were  in  the  '  cold  area.' 

At  this  point  we  requested  Captain  Calver  to  take 
a  serial  sounding,  ascertaining  the  temperature  at 
depths  progressively  increasing  by  50  fathoms,  which 
was  done  with  the  following  result : — 

Surface 11"- 8  C. 

50  fathoms 9-2 

100       „          8-4 

150       „ .  8-0 

200       „          7-5 

250       „          3-5 

300       „          0  •  G 

384  (Bottom) 0  •  8 

We  thus  ascertained  that  the  minimum  tempera- 
ture was  at  the  bottom;  and  this  we  have  found  to  be 
universally  the  case  over  the  whole  of  the  area  which 
we  have  examined,  whatever  the  bottom  temperature 
might  be.  And  we  also  ascertained  that  the  decrease 
in  heat  from  the  surface  downwards  was  by  no  means 
uniform,  but  that  while  after  passing  the  surface 
layer  it  was  tolerably  regular  for  the  first  200 
fathoms,  there  was  an  extraordinary  fall  amounting 
to  upwards  of  7'C.  from  200  to  300  fathoms,  at 
wliich  latter  depth  the  minimum  is  nearly  gained. 

The  next  few  observations.  Stations  53  to  59,  were 
all  within  the  limits  of  the  cold  area,  the  bottom  tem- 
perature at  depths  ranging  from  360  to  630  fathoms, 
nowhere  reaching  the  freezing-point  of  fresh  water; 
and  *at  one  point.  Station  59,  lat.  60°  2V  N.,  long. 
5°  41'  W.,  at  a  depth  of  580  fathoms,  the  index  stand- 
ing so  low  as  -l°-3  C.  On  Saturday  the  21st  we  took 
a  sounding  in  187  fathoms,  on  the  edge  of  the  Fjferoe 


310 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VII. 


plateau,  and  about  twenty  miles  north  of  the  pre- 
vious station,  with  a  temperature  of  6°'9C.,  and  so 
found  that  we  had  passed  the  limits  of  the  cold 
basin. 

Our  first  two  soundings  after  leaving  Thorshavn 
(Stations  61  and  62)  were  in  shallow  water  on  the 
Fseroe  Bank,  114  and  125  fathoms,  with  a  tempera- 
ture of  7°'2  and  7°*0  C.  respectively ;  but  the  next 
Station,  No.  63,  after  a  run  of  eighty  miles,  gave 
317  fathoms  and  0°-9  C,  showing  that  we  were 
once  more  in  the  cold  region.  From  that  point, 
passing  in  a  south-easterly  direction  across  the 
channel  towards  the  northern  point  of  Shetland,  we 
traversed  the  cold  area  in  its  most  characteristic 
form,  finding  at  Station  64,  lat.  61°  21'  N.,  long. 
3°  44'  W.,  a  depth  of  640  fathoms,  with  a  botto] 
temperature  of  — 1°*2  C.  Here  we  took  another j 
serial  sounding,  and  its  results  corresponded  generally] 
with  those  of  No.  52.  The  surface  temperature  wasj 
lower,  and  the  temperature  down  to  200  fathoms  some- 
what lower  ;  at  350  fathoms  it  was  a  little  higher : — 

Surface 

50  fathoms 

100 


150 
200 
250 
300 
350 
400 
450 
500 
550 
600 
G40 


O'' 

8C. 

7 

5 

7 

•  2 

6 

3 

4  • 

1 

1 

3 

0 

2 

0 

3 

0 

5 

0 

8 

-1 

0 

-1 

•0 

-1 

1 

-1 

2 

CHAP,  vn.]  DEEP-SEA  TEMPERATURES.  311 

At  this  point,  therefore,  the  ice-cold  water  of  the 
Arctic  current  filling  up  the  bottom  of  the  trough 
is  nearly  2,000  feet  deep,  while  the  temperate  water 
above  has  nearly  an  equal  depth.  The  lower  half  of 
the  latter,  however,  has  its  temperature  considerably 
reduced  by  intermixture  and  diffusion.  Pig.  55 
represents  dia grammatically  the  general  result  of 
temperature  observations  in  the  cold  area.  The 
depth  at  the  next  Station,  No.  65,  was  354  fathoms, 
showing  that  the  channel  had  begun  to  shoal  towards 
Shetland;  the  temperature  was,  however,  still  low, 
almost  exactly  0°  C.  The  next  Station,  No.  Q^^ 
eighteen  miles  further  on  towards  the  Shetland 
banks,  gave  a  depth  of  267  fathoms,  with  a  bottom 
temperature  of  7°*6  C,  the  temperature  at  the  surface 
being  ll°-3  C.  We  had  therefore  got  beyond  the 
edge  of  the  trough  filled  by  the  cold  stream,  and 
passed  into  lesser  depths  occupied  from  the  surface  to 
the  bottom  by  the  warm  southern  stratum. 

The  next  series  of  soundings,  Nos.  67  to  75,  are  either 
in  shallow  water  round  Shetland,  or  in  water  on  the 
shelving  edge  of  the  plateau,  not  deep  enough  to  reach 
the  frigid  stream.  It  is  of  some  interest  that  the 
two  soundings,  Nos.  68  and  69,  in  75  and  67  fathoms 
respectively,  to  the  east  of  Shetland,  show  a  bottom 
temperature  of  QI^'Q  C,  while  a  serial  sounding  in  the 
Avarm  area  at  the  western  entrance  of  the  Paeroe 
Channel  gives  for  the  same  depth  a  temperature  of 
about  8°*8  C.  This  circumstance,  along  with  others 
to  be  mentioned  hereafter,  would  seem  to  show  that 
a  considerable  indraught  of  cold  water  spreads  over 
the  bottom  of  the  shallow  north  sea. 

At  Stations  76  to  86,  which  are  along  the  southern 


CHAP.  VI I. j 


DEEF-SEA  TEMPERATURES. 


313 


border  of  the  cold  area,  temperature  soundings  were 
taken  mainly  with  a  view  to  define  its  southern  limit, 
and  they  are  sometimes  on  one  side  and  sometimes  on 
the  other.  The  general  result  is  indicated  on  Plate 
IV.  by  the  southern  border  of  the  shaded  space.  Nos. 
87  to  90  are  once  more  in  the  warm  area,  the  water 
reaching  a  depth  of  upwards  of  700  fathoms,  but 
maintaining,  after  the  first  300  fathoms,  a  tempera- 
ture of  from  6°  to  7°  C.  above  that  of  corresponding 
depths  in  the  cold  area.  At  Station  87,  lat.  59° 35'  Is., 
long.  9°  11'  W.,  with  a  depth  of  767  fathoms,  a  serial 
sounding  was  taken,  which  contrasts  remarkably 
with  the  series  at  Station  64.  The  general  result  of 
this  sounding  is  represented  diagrammatically  by 
Eig  56.  The  temperature  was  taken  at  every  100 
fathoms  after  the  first  200. 


Surface .11" 

50  fatboms 9 

100       „          8 

150       „          8 

200       „ 8 

300       „          8 

4(^0       „ .  7 

500       „          7 

600       „          G 

767 5 


4C. 

0 

5 

3 

2 

I 

8 

3 

1 

1 


It  will  be  seen  by  reference  to  the  chart  that  two 
nearly  parallel  series  of  soundings  were  taken,  ex- 
tending from  the  shallow  water  on  the  Scottish  side 
to  the  ed2:e  of  the  Fgeroe  Bank  close  to  the  western 
opening  of  the  F^feroe  Channel,  and  that  one  of  these 
chains,  including  Stations  52,  53,  5i,  and  86,  are  in 
the  cold  area,  while  the  other  chain  of  Stations,  48, 


314  THE  DEPTHS  OF  THE  SEA.  [chai'.  vii. 

47,  90,  49,  50,  and  51,  are  in  the  warm  area.     There 
is  no  great  difference  in  depth  hetween  the  two  series 
of  soundings ;  and  there  is  no  indication  of  a  ridged 
separating  them.     The  only  possible  explanation  ot\ 
these   two   so   widely   different  submarine   climates,] 
existing  apparently   under   the   same   circumstances^ 
and  in  close  proximity  to  one  another,  is  that  the 
Arctic  indraught  which  passes  into  the  deeper  part 
of  the  Pseroe  Channel  is  banked  in  at  its  entrance, 
by  the  warm  southern  stream  slowly  passing  north- 
wards.    There  is  a  slight  but  very  constant  depres- 
sion of  the  isothermal  lines  of  surface  temperature 
in  the  shallow  water  along  the  west  coast  of  Britain. 
This,  I  believe,  indicates  that  a  portion  of  the  cold 
Pseroe  stream  makes  its  escape,  and,  still  banked  in 
close  to  the  land  by  the  warm  water,  gradually  makes 
its  way  southwards,  so  mixed  and  diluted  as  only  to 
be  perceptible  by  its  slight  effect  on  the  lines  of  mean 
temperature.     Diagrams  55  and  56  illustrate  the  dis- 
tribution of  temperature  in  the  cold  and  warm  areas 
respectively ;  and  in  Eig.  57,  the  results  of  the  serial 
soundings  Nos.  52,  64,  and  87,  are  reduced  to  curves. 
Erom  these  diagrams,  taken  together,  it  will  be  seen 
that  in  the  first  50  fathoms  there  is  a  rapid  fall  of 
nearly  3°  C.     Station  No.  64  is  a  good  deal  farther 
north  than  the  other  two,  and  the  surface  tempera- 
ture is  lower,  so  that  the  fall,  which  is  nearly  to  the 
same  amount,  starts  from  a  lower  point.     The  surface 
temperature  is  doubtless  due  to  the  direct   heat  of 
the  sun,  and  the  first  rapid  fall  is  due  to  the  rapid 
decrease  of  this  direct  effect.    Prom  50  to  200  fathoms 
the  temperature  in  all  three  cases  falls  but  little,  re- 
maining considerably  above  the  normal  temperature 


I  I 


3 1  G  THE  DEPTHS  OF  THE  SEJ.  [chap.  vir. 

of  the  ocean  for  the  parallel  of  latitude.  At  a 
depth  of  200  fathoms,  however,  the  divergence  be- 
tween tlie  curves  of  the  warm  and  cold  areas  is  most 
remarkable.  The  curve  of  tlie  warm  area,  No.  87, 
shows  a  fall  of  scarcely  half  a  degree  at  500  fathoms, 
and  less  tlian  one  degree  more  at  767  fathoms  at 
the  bottom.  Between  200  and  300  fathoms  the  cold 
area  curves  run  down  from  8°  C.  to  0°  C,  leaving 
only  one  degree  more  of  gradual  descent  for  the 
next  300  fathoms.  The  temperature  of  the  '  hump ' 
on  the  curves  of  the  '  cold  area '  between  50  and 
200  fathoms  corresponds  so  nearly  with  that  of  the 
long  gradual  sinking  of  the  curve  of  the  warm  area 
from  the  surface  nearly  to  the  bottom,  that  it  seems 
natural  to  trace  it  to  the  same  source.  We  there- 
fore conclude  that  a  shallow  layer  of  Gulf-stream 
water  driftino^  slowlv  northwards  overlies  in  the  cold 
area  an  indraught  of  cold  water  represented  by  the 
sudden  and  great  depression  of  the  curves,  while  in 
the  warm  area  this  cold  indraught  is  absent,  the 
Gulf-stream  water  reaching  to  the  bottom. 

Tracing  the  '  warm  area '  southwards  from  the 
mouth  of  the  Fseroe  Channel  along  the  coast  of  Scot- 
land, we  find  that  the  area  between  Eseroe,  the  Lews, 
and  llockall,  is  a  kind  of  plateau  with  a  depth  of 
from  700  to  800  fathoms ;  and  we  may  be  certain  from 
analogy,  although  this  region  has  not  yet  been  actu- 
ally examined,  with  a  bottom  temperature  not  lower 
than  4°'5  C.  Commencing  opposite  Rockall,  and  ex- 
tending between  the  great  shoal  which  culminates 
in  the  llockall  fishing^  banks  and  the  sino^ular  isolated 
rock,  and  the  west  coast  of  Ireland,  there  is  a  wide 
trough  deepening  gi-adually  southwards,  and  at  length 


(HAP.  VII.]  DEEP-SEA  TEMFERATURES.  317 

continuous   with    the    general   basin   of    the   North 

1(    Atlantic. 

The  temparature  of  this  ocean  valley  was  investi- 

;  gated  with  great  care  during  the  first  and  second 
cruises  of  the  '  Porcupine '  in  1869,  and  the  results 
were  so  very  uniform  throughout  the  area  that  it 
will  be  needless  to  describe  in  detail  the  slight 
differences  in  different  localities.  These  differences, 
in  fact,  only  affected  the  surface  layer  of  the  water, 
and  depended  merely  upon  differences  of  latitude. 
The  temperatures  ifi  deep  water  may  be  said  to 
have  been  practically  the  same  everywhere.  The 
first  chain  of  soundings,  taken  by  Captain  Calver 
during  the  first  cruise  under  the  scientific  direction 
of  Mr.  Gwyn  Jeffreys,  was  between  Lough  S willy 
and  Rockall.  The  greatest  depth,  1,380  fathoms,  is 
in  the  middle  of  the  channel,  and  a  sounding  at 
that  depth,  lat.  56°  2V  X.,  long.  IV  W  W.,  gave 
a  bottom  temperature  of  2°* 8  C.  A  depth  of  630 
fathoms,  No.  23,  a  little  to  the  south  of  Rockall, 
gave  a  temperature  of  6°*4  C,  almost  exactly  the 
same  as  the  temperature  of  a  like  depth  in  the  warm 
area  off  the  entrance  of  the  Pseroe  Channel ;  and  a 
temperature  at  500  fathoms,  one  of  a  series  taken 
at  Station  21  with  a  bottom  temperature  at  1,476 
fathoms  of  2°*7  C,  was  8°'5  C,  rather  less  than  a 
degree  higher  than  the  temperature  at  a  correspond- 
ing depth  at  Station  87.  At  Station  21  the  tempera- 
ture was  taken  at  everv  250  fathoms. 

Surface 13°' 5  C. 

250  fathoms 9  •  0 

500       „  8-5 

750       „  5-8 


318  THE  DEPTHS  OF  THE  SEA.  ,[chap.  vii 

1,000  fVithoms 3°-  5C. 

1,200       „  3-3 

1,47G       , 2-7 

We  have  lisre  on  a  larg-e  scale,  as  Dr.  Carpenter 
has  pointed  out,  conditions  very  analogous  to  those 
which  exist  in  comparatively  shallow  water,  and  on  a 
small  scale  in  the  cold  area  in  the  Faeroe  Channel. 
There  is  a  surface  layer  of  ahout  50  fathoms,  super- 
heated in  August  by  direct  solar  radiation,  and,  as  we 
see  by  the  variations  of  surface  isotherm als,  varying 
greatly  with  the  seasons  of  the  year.  Next,  we  have  a 
band  extending  here  to  a  depth  of  nearly  800  fathoms, 
in  which  the  thermometer  sinks  slowly  through  a" 
range  of  about  5°  C.  Then  a  zone  of  intermixture 
of  about  200  fathoms,  where  the  temperature  falls 
rapidly,  and  finally  a  mass  of  cold  water  from  a  deptli 
of  1,000  fathoms  to  the  bottom,  through  which,  what- 
ever be  its  depth,  the  thermometer  falls  almost  im- 
perceptibly, the  water  never  reaching  the  dead  cold- 
of  the  Arctic  undercurrent  in  the  F^roe  Channel, 
and  the  lowest  temperature  being  universally  at  the 
bottom  (Fig.  58). 

The  area  investigated  during  the  second  cruise  of 
the  '  Porcupine '  at  the  mouth  of  the  Bay  of  Biscay, 
about  a  couple  of  luindred  miles  west  of  Ushant, 
may  be  regarded  as  simply  a  continuation  southwards 
of  the  tract  between  Scotland  and  Ireland  and  the 
Bockall  ridge.  As,  however,  the  depths  were  greater 
than  any  attained  on  any  foi"mer  occasion — were  so 
great,  indeed,  as  probably  to  represent  the  average 
depth  of  the  great  ocean  basins— it  may  be  well  to 
describe  the  methods  of  observation  and  the  condi- 
tions of  temperature  somewhat  in  detail. 


320  THE  DEPTHS  OF  THE  SEA.  [chap.  vit. 

The  sounding  at  Station  No.  37,  at  a  depth  of 
2;435  fathoms,  has  already  heen  fully  described  as  an 
example  of  the  most  recent  method  of  determining 
extreme  depths  with  accuracy.  Two  Miller-Casella 
thermometers,  numbered  100  and  103  respectively, 
were  lashed  to  the  sounding -line  in  their  copper 
cases,  one  a  little  above  the  other,  about  a  fathom 
and  a  fathom  and  a  half  above  the  'Hydra'  sounding- 
machine.  These  two  instruments  had  been  prepared 
and  tested  with  extreme  care,  and  had  been  employed 
throughout  the  first  cruise  ;  their  freezing-points  had 
been  ai]^ain  verified  at  Belfast  in  case  the  enormous 
pressure  to  w^iich  they  had  been  subjected  might 
have  affected  the  glass,  and  we  had  absolute  confidence 
in  their  indications.  The  indices  were  set  before  the 
instruments  were  let  down  at  the  temperature  of  the 
surface,  2r-l  C,  and  'IV  1^  C.  They  were  allowed  to 
remain  at  the  bottom  for  ten  minutes,  and  on  their 
return  to  the  surface  in  upwards  of  two  hours  and  a 
half,  they  were  unanimous  in  recording  a  minimum 
of  1°'65  C,  the  slight  differences  between  the  two 
instruments,  which  gave  the  almost  inappreciable 
error  for  one  of  them  of  0°*05  C.  at  21°  C,  being 
imperceptible  at  the  lower  temperature. 

It  had  a  strange  interest  to  see  these  two  little 
instruments,  upon  whose  construction  so  much  skilled 
labour  and  consideration  had  been  lavished,  con- 
signed to  their  long  and  hazardous  journey;  and  their 
return  eagerly  watched  for  by  a  knot  of  thoughtful 
men,  standing,  note-book  in  hand,  ready  to  register 
this  first  message,  which  should  throw  so  much  light 
upon  the  physical  conditions  of  a  hitherto  unknown 
world. 


CHAP.  VII.] 


DEEP-SEA  TEMPERATURES. 


321 


A  series  of  temperature  soundings,  at  depths  in- 
creasing progressively  by  250  fathoms,  Avas  taken  to  a 
depth  of  2,090  fathoms,  on  the   24th  of  July,  lat. 


47°  39'  N.,  long.  11°  33'  W. 


Surface     . 

17° 

•  08  C. 

250  fathoms 

.     10 

•  28 

less  th 

in  Surface 

.     7'^-  5  C 

500 

8 

8 

5J 

250  fathoms 

1  -5 

750 

5 

17 

)J 

500 

3  -G 

1,000 

3 

5 

J) 

750 

1  -7 

1,250 

3 

17 

5> 

1,000       „ 

0  -3 

1,500 

2 

9 

5> 

1,250        „ 

0  •  3 

1,750 

2 

61 

)J 

1,500 

0  •  3 

2,090 

2  • 

4 

J5 

1,750        „ 

0  -2 

The  same  two  Miller-Casella  thermometers  were 
employed  as  in  the  previous  observation. 

Another  serial  sounding  was  taken  a  few  days  late^ 
in  water  862  fathoms  deep,  somewhat  nearer  the  coast 
of  Ireland.  In  this  case  tlie  temperature  was  taken 
at  intervals  of  10  fatlioms  from  the  surface  to  a 
depth  of  50  fathoms,  and  thence  at  intervals  of 
50  fathoms  to  the  bottom.  This  was  done  to  deter- 
mine exactly  the  rate  of  diminution  of  temperature, 
and  the  exact  position  of  the  most  marked  irregu- 
larities. 


Surface     . 

17° 

22  C. 

10  fathoms 

16 

72 

less  than 

surface    .     . 

.     0° 

5C 

20 

15 

22 

less  than 

10  fathoms 

1 

5 

30 

13 

33 

20       „ 

1 

9 

40 

12  • 

44 

30       „ 

0 

9 

50 

11  • 

8 

40       „ 

0 

64 

100 

10- 

6 

50       „ 

1 

2 

150 

.     10 

5 

100       „ 

0 

'  1 

200 

10 

3 

150       „ 

0 

2 

250 

10 

11 

200       „ 

0 

2 

300 

.       9 

•  8 

250       „ 

0 

3 

Fio.  59. — Diagram  representing  the 
relation  between  depth  and  tem- 
perature off  Rockall, 


Fig.  60.— Diagram  representing  the 
relation  between  depth  and  tem- 
perature in  the  Atlantic  basin. 


CHAP.  VII.] 


DEEP-SEA  TEMPERATURES. 


323 


350 

fathoms 

9^-  5  C.     less  than    300  f 

athoms 

.     0-  3  C. 

400 

.       9  •  17 

350 

3J 

.     0-3 

450 

.       8  -7 

„         400 

>J 

.     0-5 

500 

.       8-  bb 

„         450 

J) 

.     0-15 

550 

8  •  0 

„         500 

)> 

.     0-55 

COO 

7  •  4 

550 

» 

.     0-5 

650 

6  -83 

600 

» 

.     0-6 

700 

6  -44 

„         650 

JJ 

.     0-4 

750 

5  •  83 

700 

)« 

.     0-6 

800 

5  •  55 

750 

5) 

.     0-3 

862  (Bottom) 

4  •  3 

800 

J> 

.     1-25 

The  general  result  of  these  two  series  of  soundings 
is  very  important.     The  high  temperature  reduced  by 
T'h  C.  in  the  first  series  at  250  fathoms  is  undoubtedly 
due  to  superheating  by  direct  solar  radiation.      This 
is  shawn  still  more  clearly  in  the  second  series,  where 
nearly  4°  C.  are  seen  to  be  lost  between  the  surface  and 
30  fathoms,  and  somewhat  above  2°  C.  more  between 
30  and  100  fathoms.     Prom  100  to  500  fathoms  the 
temperature  is  still  high  and  tolerably  uniform,  and 
it  falls  rapidly  between  500  and  1,000  fathoms.     A 
reference  to  the  second  series  shows  that  this  rapid 
fall  is  between  650  and  850  fathoms,  in  which  inter- 
val there  is  a  loss  of  more  than  3°  C.      This   second 
stage    of    elevated    temperature  from    250    to   700 
fathoms,  which    is   represented   graphically   by   the 
singular  'hump'   on  the  temperature  curves  in  Eig. 
61  and  Plate  YI.  would  seem  to  be  caused  by  the 
north-easterly  reflux  under  peculiar  conditions,  which 
will  be  referred  to   in   next   chapter,    of   the    great 
equatorial    current.      Prom    1,000    fathoms    down- 
wards, the  loss  of  temperature  goes  on  uniformly  at 
the    rate  of   about   0°-3  0.   for   every   250   fathoms. 
The  most  singular  feature  in  this  decrease  of  tem- 

y2 


H 

^■■1 

H 

HIHI 

H 

BlHpl 

H 

mm 

H 

HMhi 

H 

■||H|| 

H 

HIhI 

pi 

hI^H 

III 

HHiH 

Ih 

^Bl 

II 


-ail 


ciTAP.  vir.]  BEEP-SEA  TEMPERATURES.  32.) 

perature  for  the  last  mile  and  three-quarters  is  its 
absolute  uniformity,  which  appears  to  he  incon- 
sistent witli  the  idea  of  anything  like  a  current  in 
the  ordinary  sense,  and  rather  to  point  to  a  slow 
and  general  indraught  of  cold  water,  falling  in 
chiefly  by  gravitation  from  the  coldest  and  deepest 
sources  available,  to  supply  the  place  of  the  warm 
water  constantly  moving  to  the  northward. 

In  1870,  Mr.  Gwyn  Jeffreys  took  his  first  tem- 
perature observations  at  the  mouth  of  the  Channel, 
and  found  them  to  correspond  very  closely  with 
those  of  the  previous  year ;  on  the  9tli  of  July  the 
bottom  temperature  at  358  fathoms,  Station  6  PL  V., 
was  lO'^'OC,  against  9°*8  C,  at  about  the  same  depth 
in  a  serial  sounding  in  1869,  in  the  immediate 
neighbourhood.  The  next  few  soundings,  Stations 
10  to  13,  are  in  comparatively  shallow  water,  off  the 
coast  of  Portugal,  while  the  next  four  Stations,  a 
little  north  of  Lishou,  may  serve  as  an  example  of 
the  temperatures  to  a  considerable  depth  in  that 
latitude.  Station  14,  469  fathoms,  with  a  surface 
temperature  of  18'''3  C,  has  a  bottom  temperature  of 
10°-7  C. ;  Station  15,  at  722  fathoms,  a  temperature 
of  9°'7  C. ;  Station  16,  at  994  fathoms,  4°-4  C. ;  and 
Station  17,  at  1,095  fathoms,  4°-3  C.  This  result  is 
very  similar  to  that  which  we  met  with  in  1869  off 
Ushant.  With  certain  differences,  which  seem  to  de- 
pend mainly  upon  the  differences  of  latitude,  we  have 
the  same  phenomena — a  thin  surface-layer,  superheated 
by  the  direct  rays  of  the  sun;  a  layer  of  warm  water 
through  which  the  temperature  descends  very  slowly 
down  to  800  fathoms;  a  zoue  of  intermixture  and 
rapid    descent    of    the   thermometer   of   nearly  200 


326  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

fathoms  in  thickness  ;  and  finally  the  deep  cold  layer 
into  which  these  soundings  do  not  penetrate  very  far, 
through  which  the  temperature  sinks  almost  imper- 
ceptibly from  4°  C.  The  difference  between  these 
soundings  and  those  of  the  year  before  at  the  mouth 
of  the  Bay  of  Biscay  is  that  the  temperatures  at  all 
depths  are  somewhat  higher. 

I  refrain  for  the  present  from  going  into  any  detail 
with  regard  to  the  distribution  of  temperature  in  the 
Mediterranean,  further  than  to  give  a  mere  outline  of 
the  remarkable  conditions  which  were  observed  there 
by  Dr.  Carpenter. 

Dr.  Carpenter's  observations  were  principally  con- 
fined to  the  western  basin  of  the  Mediterranean,  and 
during  the  months  of  August  and  September  the 
surface  temperature  averaged  between  23°  C.  and 
26°  C.  On  two  occasions  only  the  surface  tempera- 
ture fell  considerably  lower,  and  the  fall  was  attri- 
buted in  both  cases  to  the  influence  of  the  colder 
surface  current  passing  from  the  Atlantic  through 
the  Straits  of  Gibraltar.  The  following  table  of  the 
series  taken  at  Station  53  gives  about  the  average  rate 
of  fall  of  temperature  for  the  first  100  fathoms  : — 

Surface 25°-  0  C. 

5  fathoms 24  •  5 

10       „ 21-6 


20 
30 
40 
50 
100 


16-4 
15-  5 
14-  1 
13-  6 
13-0 


and   Dr.  Carpenter   made  the    remarkable    observa- 
tion   that    "whatever   the  temperature   was  at  100 


4 


Fig.  62.— Diagram  representing  the  relation  between  depth  and  temperature,  from  the  tempera 
ture  observations  taken  between  Cape  Finisterre  and  Cape  St.  Vincent,  August  1870. 


328 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VII. 


fathoms,  that  was  the  temperature  of  the  whole 
mass  of  water  heneath,  down  to  the  greatest  depth 
explored."  The  temperature  at  100  fathoms  varies 
very  little  from  13°  C.  (555°  Eahrenheit),  and  the 
Mediterranean  attains  in  many  places  a  depth  of  up- 
wards of  1,500  fathoms,  so  that  here  we  have  the 
strange  phenomenon  of  an  underlying  mass  of  water, 
1,400  fathoms  deep,  of  a  uniform  moderate  tempera- 
ture ;  a  state  of  things  singularly  different  from  that 
which  obtains  at  like  depths  in  the  Atlantic.  Dr. 
Carpenter's  ingenious  speculations  as  to  the  cause 
of  this  difference  will  be  considered  later. 


vaaV  chuech  in  sudero. 


CHAP.  VII.] 


DEEP-SEA  TEMPERATURES, 


329 


APPENDIX   A. 

Surface   Temperatures   ohse'tDed  on    hoard   H.M.S.   '  Porcupitu 
during  the  Summers  of  1869  and  1870. 

I.  Temperatures  observed  in  1869. 


e 

es 

g 

£  i 

Date  and  Position. 

i 

p 

!'■< 

1 

Date  and  Position. 

1      ^ 

\      § 

fe 

P  :2 

£02 

W 

1= 

^1 

go 

11 

Deg. 

Deg. 

Deg. 

De- 

Cent. 

Cent. 

Cent. 

cent. 

i 

May  28th      .     . 

2 

10-0 

9-4 

May  30th     .     . 

4 

10-0 

9-4 

■ 

4 

lO'O 

10-2 

6 

10-8 

10-8 

6 

8 

12-2 

iri 

8 

10 

15-0 

11-1 

10 

10-0 

10-5 

In  Valentia  .     . 

Noon. 

15-0 

12-7 

Off    the    Great) 
Skelligs     .     .  ] 

Noon. 

9*4 

10-8 

2 
4 

12-8 
12-5 

12-2 
11-4 

2 

11-9 

6 

11-4 

iri 

4 

11-6 

111 

8 

6 

11-4 

io 

10-0 

iri 

8 

Midn. 

9-4 

111 

10 

11-6 

10-2 

May  31st .     .     . 

2 

9-4 

10-8 

Midn. 

10-0 

10-6 

4 

10-0 

11-1 

May  2.9th      .     . 

2 

6 

11-1 

111 

4 

7-2 

8 

13-3 

11-1 

1 

6 

11*6 

10-2 

10 

13-3 

11-1 

8 
10 

111 
13-3 

10-8 
12-7 

Lat.    5r52'N.  ) 
Long.  11°34'W. 

Noon. 

13-9 

11-6 

In  Dingle  Bay  . 

Noon. 

13-9 

11-6 

2 

13-9 

11-4 

2 

13-9 

11-4 

4 

12-7 

4 

127 

11-4 

6 

12-2 

11-9 

6 

10-5 

8 

12-2 

11-6 

8 

10-0 

10-6 

10 

11-6 

11-6 

10 

11-6 

1 

Midn. 

11-9 

11-9 

f 

Midn. 

11-1 

June  1st     .     .     . 

2 

12-2 

12-2 

May  30th      .     . 

2 

11*6 

' 

4 

12-2 

12-2 

330 


THE  DEPTHS  OF  THE  SEJ. 


[chap.  VII. 


! 
I 

i 

2 

^i 

£ 

tm 

1 

_g 

fS^ 

s 

Date  and  Position. 

1 

1         i< 

1 

1! 

So 

4) 

II 

Date  and  Position. 

1 

§ 

So 

el 

i 

1 

H 

^% 

EH 

H, 

Deg. 

Deg. 

Deg. 

Deg.i 

Cent. 

Cent. 

Cent. 

Cent 

June  1st  .     .     . 

6 

12-2 

11-9 

June  4th  .     .     . 

2 

13-3 

11-6^ 

8 

13-0 

11-9 

4 

13-3 

11-6 

10 

13-9 

11-9 

6 

12-8 

11-9 

Lat.    5r22'N.  \ 
Long.  12°  26' W.  ] 

Noon. 

14-4 

11-9 

8 
10 

12-8 
12-2 

12-2, 
11-4 

2 

14-4 

12-2 

Midn. 

11-9 

11-9 

4 

12-2 

11-6 

June  5th  .     .     . 

2 

11-9 

11-9. 

6 

13-3 

11-9 

i 

4 

11-6 

11-6 

! 

Q 

12-2 

11-9 

6 

12-7 

iri 

10 

11-9 

12-2 

8 

12-7 

iri 

Midn. 

11-6 

11-9 

10 

12-7 

11-6 

;  June  2nd .     .     . 

2 

11-9 

11-9 

In  Galway  Dock 

Noon. 

16-1 

13-3 

1 

4 

11-1 

11-9 

2 

15-5 

150 

6 

10-5 

11-9 

4 

13-9 

8 

11-6 

6 

15-5 

1 

10 

12-2 

12-2 

8 

13-3 

;  Lat.    52°   8'N.  ) 
Long.  12°  50'  W.  ] 

Noon. 

15-0 

12-2 

10 
Midn. 

13-3 
13-9 

2 

14-4 

12-2 

June  6th  .     .     . 

2 

13-3 

4 

15-0 

12-2 

4 

12-7 

■6 

13-9 

12-2 

6 

8 

11-1 

11-9 

8 

10  " 

"11-4 

11-9 

10 

14-4 

Midn. 

iri 

11-9 

In  Gahvay  Dock 

Noon. 

12-2 

June  3rd  .     .     . 

2 

11-1 

11-6 

2 

17-2 

4 

10-8 

11-6 

4 

19-4 

. 

6 

11-1 

11-9 

6 

19-4 

8 

12-7 

11-6 

8 

10 

15-0 

11-9 

10 

13-9 

Lat.     52^  26'  N.  ) 
Long.  ir41'W.  C 

Noon. 

13-3 

11-6 

June  7th  .     .     . 

Midn. 
2 

13-3 
13-3 

2 

147 

11-9 

4 

12-7 

4 

130 

12-2 

6 

* 

6     1 

11-6 

12-2 

8 

8 

11-1 

11-8 

10 

16-1 

10 

111 

11-6 

in  Galway  Dock 

Noon. 

18-3 

'-. 

Midn. 

10-8 

11-6 

2 

17-7 

X 

June  4th  .     .     . 

2 

11-1 

11-6 

4 

17-7 

♦ 

4 

iri 

11-6 

6 

17-2 

6 

111 

11-6    1 

8 

15-0 

8 

10-8 

il-6    1 

10 

13-9 

10 

10-5 

11-6    \ 

Midn. 

12-2 

Lat.    52°  14'  N.  \ 
Long.  11*45'W.  ] 

Noon. 

10-5 

11-1 

June  8th  .     .     . 

2     1 
4 

11-1 
10-0 

•' 

CHAP.  VII.] 


DEEP-SEA  TEMPERATURES. 


331 


Date  and  Position. 


June  8th .     .     . 
[n  Galway  Dock 


I 


e9th  . 


In  Galway  Dock 


June  lOth     .     . 


Lat.    53"16'N. 
Long.  11°52'W. 


June  11  til 


Lat.     53"  22'  N. 
Lonor  13°23'W. 


6 

8 

10 

Noon. 

2 

4 

6 

8 

10 

Midn. 

2 

4 

6 

8 

10 

Noon. 

2 

4 

6 

8 

10 

Midn. 

2 

4 

6 

8 
10 

Noon. 

2 

4 

6 

8 

10 

Midn. 

2 

4 

6 

8 
10 

Noon. 

2 
4 


2 

So 

If 

Deg. 
Cent. 

Deg. 
Cent. 

i  10-0 

1 

1  17-2 

21-1 

!  20-5 

i  20-5 

17-7 

'  20-0 

16-6 

15-0 

11-6 

12-7 

iri 

12-5 

7-2 

12-2 

7-7 

11-6 

10-5 

12-2 

12-7 

12-5 

16-1 

13-3 

19-4 

13-9 

1  17-4 

13-9 

1  17-2 

13-6 

1  15-0 

12-5     i 

1  11-4 

12-7 

10-5 

12-5 

10-5 

12-5 

10-0 

11-6     1 

10-5 

11-6 

10-2 

12-2    |i 

12-2 

12-5 

11-6 

12-5 

12-7 

12-5 

13-3 

12-7 

12-2 

12-2     ! 

11-6 

12-7 

10-5 

12-3 

10-0 

12-3 

10-0 

12-3 

I  10-0 

12-2 

1  10-0 

12-2 

111 

12-5     ; 

111 

12-5 

12-5 

12-5 

15-0 

12-2 

13-9 

12-7 

14-4 

12-7 

Diite  and  Position. 


June  11  til 


June  12tli 


Lat. 
LontJ 


53"24'N 
15°  24'  W. 


June  13tli 


Lat. 
Lone 


53°  28'  N. 
15°  08'  W. 


June  14th 


Lat. 
Lone 


53°  43'  N. 
13°  48'  W. 


June  15th 


. 

£ 

.    £S 

3 

-tS 

-u  .  • 

-u    si 

i 

i-^ 

M 

|=s 

11 

H 

^=o 

Deg. 

Deg. 

Cent. 

Cent. 

6 

11-9 

12-7 

8 

10-5 

12-7 

10 

111 

12-2 

Midn. 

10-0 

12-2 

2 

10-0 

12-2 

4 

10-2 

12-3 

6 

11-1 

12-9 

8 

11-4 

13-0 

10 

12-2 

12-7 

Noon. 

12-2 

12-7 

2 

11-1 

12-7 

4 

12-2 

12-7 

6 

10-8 

13-0 

8 

iri 

12-9 

10 

11-1 

12-5 

Midn. 

10-5 

12-3 

2 

10-5 

11-9 

4 

10-0 

12-2 

6 

9-1 

12-2 

8 

9-7 

11-9 

10 

9-4 

12-0 

Noon. 

10-8 

12  2 

2 

10-5 

12-5 

4 

11-4 

12-2 

6 

11-1 

12-2 

i       8 

10-7 

12-3 

!       10 

ll'l 

12-2 

!  Midn. 

11-1 

12-2 

1       2 

111 

12-2 

4 

11-4 

12-2 

6 

11-4 

11-9 

8 

11-9 

12-5 

10 

11-1 

12-2 

Noon. 

13-3 

12-2 

1       2 

11-7 

12-2 

4 

13-0 

12-2 

6 

12-7 

12-2 

!       8 

iri 

11-8 

I     10 

iri 

iri 

!  Midn. 

11-1 

11-4 

1       2 

10-8 

iri 

332 


THE  DEPTHS  OF  THE  SEJ. 


[chap.  VI t. 


i 

i     £ 

ti 

1 

£ 

fit 

3 

a.rt 

Date  and  Position. 

3 

.F 

I! 

1 

Date  and  Position. 

1 

5  o 

Sm 

1 

S  "3 

z^^ 

H 

"o 

1 

H 

H=- 

I 

Reg. 

Deg. 

Deg. 

Deg 

Cent. 

Cent. 

Cent. 

Cent 

June  15th     .     . 

4 
6 

10-8 

iri 

11-6 
11-6 

Lat.     54°10'N.  ) 
1  Long.  10°  59'  W.  S 

Noon. 

12-5 

12-2 

8 

14-4 

11-6 

2 

12-9 

12-2 

10 

12-2 

11-6 

4 

12-7 

12-4 

Lat.     53°47'N.   ( 
Long.  13"  14'  VV. 

Noon. 

12-7 

10-6 

6 

8 

127 
11-9 

11-8 
11-8 

2 

13-6 

11-6 

10 

11-4 

11-6 

4 

13-0 

11-6 

Midn. 

11-4 

11-4 

6 

13-9 

11-8 

June  19th     .     . 

2 

11-1 

11-6 

8 

10-8 

11-8 

4 

111 

111 

10 

10-8 

11  6 

6 

11-6 

11-8 

Midn. 

10-5 

11-1 

8 

11-6 

12-2 

June  16th      .     . 

2 

10-0 

11-7 

10 

13-9 

11-8 

4 

10-2 

11-4 

At  Killibegs .     . 

Noon. 

13-9 

11-9 

6 

12-7 

11-5 

2 

13-3 

12-2 

8 

12-0 

11-5      ; 

4 

12-2 

12-2 

10 

13-9 

11-6 

6 

11-6 

12-3 

Lat.     54°    2'N.  \ 
Long.  12"  14'  W.  ] 

Noon. 

15-0 

11-6 

8 
10 

13-0 
11-1 

12-7 
12-2 

2 

13-9 

11-9 

Midn. 

10-5 

12-2 

4 

13-3 

12-1    i 

June  20th      .     . 

2 

10-6 

11-9 

6 

12-2 

11-6 

4 

11-1 

11-6 

8 

J  0-2 

111    ' 

6 

11-6 

11-6 

10 

11-1 

11-4 

8 

12-7 

12-2 

Midn. 

11-4 

11-4    1 

10 

13-0 

11-9 

June  17  th     .     . 

2 

11-6 

11-6    1 

At  Killibegs .     . 

Noon. 

13-9 

12-2 

4 

11-6 

11-6    i 

2 

15-0 

12-2 

6 

11-9 

11-8 

. 

4 

14-4 

12-5 

8 

13-6 

11-6    ; 

6 

14-4 

12-5 

10 

12-5 

11-6   ; 

8 

12-2 

12-5    ! 

Lat.     54''2rN.  ) 
Long.  ir43'  W.  ] 

Noon. 

13-9 

11-8    \ 

10 
Midn. 

10-0 
10-8 

12-2    1 
12-5    1 

■    2 

13-3 

11-9 

June  21.st      .     . 

2     ■ 

11-1 

12-2    ! 

4 

13-3 

11-9    i 

^     i 

11-1 

12-2 

6 

12-2 

11-9 

6 

11-8 

12-2 

8 

12-2 

116 

8     ' 

12-2 

12-2    i 

10 

11-9 

11-6 

10 

13-0 

12-2 

. 

Midn. 

12-2 

11-6 

At  Killibegs .     . 

Noon. 

15-0 

12-5    i 

June  18th     .     . 

2 

11-6 

11-6 

2 

15-3    i 

12-2 

4 

11-6 

12-0 

4     , 

14-4    1 

12-5 

6 

12-2 

12-0 

6 

13-0    i 

12-2 

8 

12-2 

121 

8     i 

11-6 

12-3 

10 

12-2 

12-2    ! 

10    : 

i 

! 

11-1 

11-6 

CHAP.  VII.] 


DEEP-SEA  TEMPERATURES. 


333 


Date  aud  Position.       i 

j 

1 

i 

l! 
r 

Temperature 
of  Sea-8urlace. 

Date  aud  Position. 

1 

1 

o 

I! 

11 

June  21st      .     . 

i 

Midn. ! 

Deg. 
Cent. 
10-5 

Ueg.                                                   1 

Cent.     1 

12-2    1|  June  25th      .     .     i 

4 

Deg. 
Cent.    I 
15-0    1 

Deg. 
Cent 
150 

June  22nd     .     . 

2     1 

iri 

11-8 

! 

6 

16-1 

13-9 

j 

4 

iri 

11-9 

8 

15-0 

14-1 

! 

6 

iri 

11-6 

i 

10 

15-5 

15-5 

J 

8     ' 

11-6 

12-0 

Midn.  1 

14-4 

15-5 

10 

13-3 

12-2 

June  26th      .     .     i 

2     1 

14-1 

15-8 

At  Killibegs .     . 

Noon. 

13-3 

12-2    1 

4 

13-9 

15i) 

2     } 

13-9 

12-3 

6 

13-9    ! 

13-3 

4    ! 

13-3 

12-2 

8 

15-3 

13-6 

6 

12-2 

12-2 

10 

18-0    1 

14-4 

8 

1    In  Donegal  Bay 

Noon. 

19-1    1 

13-9 

10 

11-1 

12-5    || 

2 

22-2 

15-3 

Midn. 

11-1 

11-9 

4 

19-4    j 

16-1 

June  23rd     .     . 

2 

10-8 

12-2 

6 

16-6 

15-5 

4 

iri 

12-2 

8 

15-5 

15-5 

6 

12-4 

12-2 

10 

12-7 

15-2 

8 

13-9 

12-2 

Midn. 

12-5 

15t 

. 

10 

15'5 

12-5 

1  June  27th     .     . 

2 

iri 

14-^ 

At  Killibegs .     . 

Noon. 

16-6 

12-5 

4 

11-4 

14-^ 

' 

2 

15-5 

12-5 

6 

12-7 

131 

; 

4 

17-7 

12-7 

1 

8 

13-6 

131 

:  . 

6 

16-6 

13-3 

10 

15-5 

14-z 

8 

13-3 

130 

At  Killibegs .     . 

Noon. 

16-6 

14-' 

10 

13-6 

13-3 

2 

20-0 

15-( 

Midn. 

12-7 

13-0 

4 

17-2 

14-^ 

June  24th     .     . 

2 

12-7 

13-3 

j 

6 

13-3 

13- 

i       4 

13-3 

13-3    II 

8 

13-3 

13- 

1       6 

14-4 

13-5 

10 

13-3 

13- 

'       8 

15-3 

13-3    !' 

Midn. 

13-3 

13- 

10 

1  16-6 

13-5       June  28th      .     . 

2 

12-7 

13- 

At  Killibegs .     . 

Noon. 

;  17-5 

13-5 

j 

4 

12-7 

12- 

2 

17-7 

13-9 

6 

1  12-7 

12- 

4 

17-7 

14-1 

1 

8 

1  13-3 

13- 

i       6 

17-2 

15-0     i 

10 

■\  13-9 

13- 

i       8 
1     10 

16-1 
14-7 

14-1     1  Lat.     54°54'N.  \ 
15-0     !  Long.  10°  59' W.  f 

Noon. 

14-7 

13- 

,  Mirn. 

14-7 

15-3 

2 

14-7 

13- 

June  25th     .     . 

2 

14-4 

14-4 

4 

13-9 

13- 

4 

14-1 

14-4 

6 

13-0 

\^- 

i 

'       6 

13-9 

13-6 

8 

13-6 

V^' 

1 

8 

18-3 

14-4 

10 

12-7 

13- 

'     10 

20-0 

13-9 

Midn. 

12-9 

13- 

At  Bundoran 

Noon. 

20'.5 

16-6       June  29th     .     . 

2 

12-7 

13- 

!          2 

23-9 

16-6 

4 

12-2 

13- 

! 

334 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VII. 


i 

ll 

i 

2 

3 

IT 

If 

Date  and  Position. 

1 

so 

Sec 

1    si 

1      Date  and  Position. 

j 

3 

12 

H 

H=5 

H 

H^J 

Dg. 

Deg. 

Deg. 

Deg. 

Cent. 

Cent. 

Cent. 

Ceni 

June  29th     .     . 

6 

13-6 

13-3 

July  2nd  .     .     . 

i       4 

16-2 

H-g" 

8 

14-4 

13-3 

6 

15-5 

14-&. 

10 

16-6 

13-9 

1 

8 

14-7 

14-4s 

Lat.    55°  11' N.  ) 
Long.ll°31'W.  j 

Noon. 

16-6 

14-4 

10 
Midn. 

15-0 
14-4 

14-6 
13-9 

2 

16-1 

15-0 

July  3rd  .     .     . 

2 

13-9 

13-9 

4 

15-5 

14-4 

4 

13-3 

13-9 

6 

15-5 

14-4 

6 

14-9 

14-1 1 

8 

15-0 

14-4 

8 

15-5  . 

141 1 

10 

13-6 

13-9 

10 

16-1 

14-0 1 

Midn. 

13-3 

13-9 

Lat.     56°58'N.  ) 
Long.  13°  17'  W.  j 

Noon. 

13-91 

:: 

June  30tli     .     . 

2 

13-0 

14-1 

15-3 

4 

13-3 

14-0 

2 

16-9 

14-4 

6 

16-6 

13-9 

4 

16-1 

13-9 

8 

18-0 

13-9 

6 

14-7 

13-6 

10 

16-1 

14-4 

8 

13-9 

12-5 

Xat.     55°44'N.   ) 
Long.  12°  53'  W.  ] 

Noon. 

16-4 

14-4 

10 
Midn. 

13-3 

12-7 

12-6 
12-2 

2 

17-7 

14-5 

July  4tli  .     .     . 

2 

13-4 

13-6 

4 

17-7 

14-4 

4 

13-9 

13-9 

6 

15-8 

15-0 

6 

13-6 

14-0 

8 

15-0 

15-0 

8 

14-1 

13-6 

10 

14-4 

15-3 

10 

14-7 

14-7 

July  1st    .     .     . 

Midn. 
2 

13-6 
12-7 

14-4 
13-9 

Lat.     56°47'N.  ) 
Long.  12°49'W.  1 

Noon. 

15-0 

13-9 

4 

13-3 

13-9 

2 

14-4 

14-7 

6 

15-5 

14-4    i 

4 

14-4 

14-8 

8 

16-3 

14-4 

6 

13-9 

14-8 

10 

17-3 

14-7 

8 

13-9 

14-9 

Noon. 

17-2 

14-8 

10 

13-9 

16-0 

2 

17-2 

15-5 

Midn. 

13-3 

14-7 

4 

16-6 

15-0 

July  5th  .     .     . 

2 

12-7 

15-0 

6 

15-0 

14-4  : 

4 

13-3 

15-0 

8 

14-4 

14-4    1 

6 

13-9 

14-7 

10 

14-1 

14-1 

8 

13-9 

14-7 

Midn. 

14-1 

14-1    1 

10 

14-4 

14-7 

July  2nd  .     .     . 

2 
4 

14-1 
14-1 

13-9    1 
14-0 

Lat.    56°41'N    ( 
Long.  12°  56'  W.  (  i 

Noon. 

13-9 

14-7 

6 

15-0 

14-1 

1 

2 

14-4 

15-0 

8 

15-5 

14-1 

4 

13-3 

15-0 

10 

15-5 

14-4    1 

6 

12-7 

14-4     J 

Lat.    56°    9'N.  ) 
Long.  14^  10'  AV.  ( 

Noon. 

17-7 

14-4 

8 
10 

12-2 
12-5 

14-1 
14-4   I 

1 
1 

2 

i 

n-4 

14-7 

Midn. 

12-5 

14-4 

\ 

CHAP.  VI J.] 


DEEP-SEA  TEMPERATURES. 


335 


si 

2 

s| 

Date  and  Position. 

1 

1° 

is 

II     j 

Date  and  Position. 

ll 

H 

H-     1 

H 

^•o 

Deg. 

Deg 

Deg. 

Deg. 

Cent. 

Cent.    ' 

Cent. 

Cent. 

July  6th  .     .     . 

2 

12-2 

13-9    1 

In  Lough  Swilly 

Noon. 

15-8 

13-3 

j 

4 

12-7 

13-9 

2 

16-1 

13-3 

6 

12-4 

13-8 

4 

15-5 

13-0 

8 

13-9 

14-1    j 

6 

15-3 

13-3 

10 

14-1 

13-9    1 

8 

13-9 

13-3 

Lat.    56°22'N.  / 

Noon. 

13-9 

10 

12-2 

13-3 

Long.  irS/'W.  \ 

Midn. 

11-6 

12-7 

2 

15-0 

July  10th      .     . 

2 

11-6 

13-6 

4 

15-3 

14-1 

4 

12-2 

13-6 

6 

13-9 

14-4 

6 

14-1 

13-0 

8 

13-3 

14-4 

8 

16-1 

13-4 

10 

12-0 

13-9 

10 

16-1 

13-4 

Midn. 

11-1 

13-3 

In  Lough  Foyle 

Noon. 

17-7 

14-4 

July  7th  .     .     . 

2 

12-7 

13-3 

2 

17-7 

15-0 

4 

14-1 

13-3 

4 

18-3 

14-7 

> 

6 

14-7 

13-3 

6 

16-1 

14-4 

8 

14-7 

13-3 

8 

14-4 

13-9 

10 

15-0 

13-4 

10 

13-9 

-13-3 

i 

Lat.    55°55'N.  \ 
Long.  10°  17'  W.  } 

Noon. 

15-0 

13-3 

July  11th      .     . 

Midn. 

2 

14-4 
15-0 

13-9 
14-4 

2 

15-0 

13-9 

4 

13-9 

14-4 

4 

15-0 

13-6 

6 

14-7 

13-9 

6 

15-0 

13-9 

8 

16-3 

13-9 

8 

15-0 

13-9 

10 

16-6 

13-6 

10 
Midn. 

14-4 
14-4 

13-3 
13-3 

At  Moville,          ) 
Lough    Foyle  ] 

Noon. 

18-9 

14-4 

j 

July  8th  .     .     . 

2 

14-4 

13-9 

2 

20-5 

15-5 

A 

4 

14-4 

13-6 

4 

21-1 

15-0 

6 

15-5 

13-9 

6 

18-9 

14-4 

8 

15-5 

13-9 

8 

18-0 

14-4 

10 

15-0 

13-9 

10 

15-8 

13-9 

Lat.  56°    6'  N.    \ 
Long.  9°  36' W.   ] 

Noon. 

15-0 

13-3 

July  12th      .     . 

Midn. 

2 

15-8 
15-3 

14-4 
15-0 

2 

14-7 

13-6 

4 

13-0 

14-7 

4 

15-0 

13-6 

6 

13-9 

11-4 

6 

13-3 

13-9 

8 

15-5 

11-1 

8 

13-3 

13-6 

10 

16-1 

10-5 

10 
Midn. 

13-3 
12-7 

13-9 
12-7 

Off    Belfast         ") 
Lough  .     .     . ) 

Noon. 

15-5 

11-1 

July  9th  .     .     . 

2 

12-2 

13-9 

2 

16-1 

11-1 

4 

12-2 

12-7 

4 

13-9 

14-4 

6 

6 

14-4 

14-4 

8 

14-1 

13-3 

8 

14-4 

14-1 

10 

15-5 

13-3 

10 

12-7 

12-2 

336 


Date  and  Position. 


THE  DEPTHS  OF  THE  SEA. 

CHAP. 

V'll. 

£ 

ti 

2 

£§•  : 

s 

^■^ 

s 

Pt^ 

1 

S  o 

11 

11 

Date  and  Position. 

^ 
S 

1" 

si 
il  > 

H 

^■5 

H 

H^ 

Deg. 

Deg. 

Deg. 

Deg. 

Cent. 

Cent. 

Cent. 

Cent. 

Midn. 

12-2 

11-6 

July  16th      .     . 

4 

16-1 

19-4 

2 

10-5 

13-3 

! 

6 

16-1 

18-9 

4 

iri 

13-3 

8 

17-7 

18-9 

6 

12-2 

13-3 

10 

17-2 

18-9 

8 

13-3 

13-6 

1 

Midn. 

14-7 

18-9 

10 

13-3 

14-1 

,  July  17th      .     . 

2 

127 

18-3 

Noon. 

15-5 

15-5 

4 

12-2 

17-2 

2 

17-2 

17-2 

6 

16-4 

18-3  1 

4 

16-6 

17-2 

8 

17-7 

18-3  f 

6 

17-7 

17-2 

10 

19-4 

18-9  1 

8 

15-5 

17-2 

At  Belfast     .     . 

Noon." 

26-1 

19-7  1 

10 

12-2 

16-6 

2 

18-9 

13-9 

Midn. 

11-6 

16-6 

4 

15-3 

11-6 

2 

13-3 

16-6 

6 

14-7 

11-6 

4 

13-3 

16-6 

8 

15-0 

12-7 

6 

14-1 

16-3 

10 

15-0 

13-9 

8 

15-8 

16-6 

Midn. 

16-6 

15-5 

10 

17-5 

16-6 

'July  18th      .     . 

2 

16-1 

Noon. 

17-8 

16-6 

4 

15-5 

2 

18-3 

16-6 

6 

16-1 

4 

17-8 

8 

15-5 

6 

10 

16-9 

8 

OffTuskarL.H. 

Noon. 

16-6 

10 

16-1 

2 

18-9 

Midn. 

16-1 

16-6 

4 

19-4 

2 

15-5 

16-1 

6 

17-9 

4 

15-0 

16-6 

8 

19-4 

6 

16-6 

16-1 

10 

18-0 

8 

18-3 

16-4 

Midn. 

17-7 

10 

20-5 

17-7 

July  19th      .     . 

2 

16-1 

Noon. 

21-4 

\ 

4 

15-5 

2 

21-1 

6 

16-3 

4 

21-1 

8 

19-7 

6 

20-5 

17-2 

10 

21-6 

8 

19-4 

17-7 

At  Haulbowline 

Noon. 

22-8 

10 

19-4 

17-2 

2 

20-0 

Midn. 

17-7 

17-2 

4 

2 

17-2 

17-2 

6 

20-0 

4 

16-6 

17-2 

8 

17-2 

17-4 

6 

17-5 

17-2 

10 

16-6 

16-6 

8 

18-9 

17-2 

Midn. 

16-6 

16-6 

10 

22-5 

17-7 

July  20th      .     . 

2 

16-9 

17-7 

Noon. 

22-5 

18-9 

4 

16-6 

18-0 

2 

17-2 

18-9 

1 

6 

17-6 

18-3 

CHitt«v^JI.] 


DEEP-SEA  TEMPERATURES. 


33 


Hate  and  Position. 


July  20th      .      . 

Laf.  50°  28'  N. 
Lonor.  9=^  37'  W. 


July  21st 


Lat.     48°  51'  N.  ^ 
Long.  11°   8'W.  j" 


July.  22nd 


Lat.    47°  38'  N. 
Lonor.  12°11' W. 


July  23rd 


Lat.    47°39'N. 
Long.  ir52'W. 


10 

Noon. 

2 

4 

6 

8 

10 

Midn. 

2 

4 

6 

8 
10 

Noon. 

2 

4 

6 

8 

10 

Midn. 

2 

4 

6 

8 
10 

Noon. 

2 

4 

6 

8 

10 

Midn. 

2 

4 

6 

8 
10 

Noon. 

2 


Temperature 
of  Sea-Surface. 

Deg. 

Cent. 

peg.     1 
Cent,    i 

20-5 

18-3    1 

21-1 

18-9 

22-2 

•18-9 

20-8 

19-7 

20-0 

19-4 

20-0 

18-9 

18-6 

18-3 

17-7 

18-3 

17-2 

18-0 

17-7 

17-7 

17-2 

16-9     1 

17-7 

17-5     1 

17-7 

17-5 

18-9 

17-5 

19-4 

17-5   " 

20-8 

17-2 

18-3 

17-2 

18-3 

17-2 

18-0 

17-7 

17-7 

17-7 

17-7 

17-7 

17-7 

16-9 

17-7 

17-7 

18-3 

18-3 

18-9 

18-0 

17-2 

17-7 

19-4 

18-3 

19-4 

18-3 

20-0 

18-3 

18-9 

18-3 

:  17-5 

18-3 

17-5 

18-3 

17-2 

18-0 

17-2 

18-0 

16-6 

18-3 

17-7 

17-7 

19-4 

18-0 

19-1 

18-0 

20-0 

18-0 

20-0 

18-3 

Date  and  Position. 


July  23rd      . 


July  24th 


Lat.    47°  40'  N. 
Long.  11°  34' W. 


July  25th 


Lat.     49°    I'N. 
Long.  12°22' W. 


July  26th      . 


Lat.     49°    O'N. 
Long.  11°58'W. 


4 
6 

10. 

Midn. 

2 

4 

6 


10 

Noon. 

2 
4 
6 


10 
Midn. 

2 

4 

6 

8 
10 

Noon. 

i 

i       2 

I       4 

1  ^ 
!       8 

I  1^ 
'  Midn. 

2 

;     4 

J  6 
I  8 
I     10 

:  Noon. 

2 
4 
6 
8 
10 
Midn. 


Deg. 
Cent. 

17-2 
18-9 
17-5 
17-2 

17-2- 

17-2 

17-5 

18-6 

18-9 

18-3 

19-4 
18-9 
18-0 
18-0 
18-3 
17-7 
17-2 
16-9 
16-6 
17-7 
18-0 

18-9 

18-3 
18-3 
18-3 
19-4 
18-3 
18-9 
16-1 
16-1 
17-2 
16-1 
18-9 

18-9 

17-2 
16-9 
16-9 
16-4 
16-1 
15-8 


338 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VII. 


£ 

,i  \ 

Date  and  Position. 

p3 

1 

So 

emperatu 
Sea-Surfa 

Date  and  Position. 

1 

fc 

c  o 

II 

So 

EH 

H 

H^ 

Deg. 

1 

Deg.     i 

Deg. 

Deg. 

Cent. 

Cent.    1 

Cent. 

Cent. 

July  27th      .     . 

2 
4 

15-5 
15-0 

17-7 
17-2 

Lat.     51°   5'  N. ) 
Long.  11°  22' W.J 

Noon. 

17-7 

15-8 

6 

17-2? 

17-5 

2 

17-7 

8 

14-6 

17-5 

4 

17-5 

16-1 

10 

18-9 

17-5 

6 

17-2 

16-6 

Lat.    49°  10'  N.  ) 
Long.  12°45'W.  ( 

Noon. 

18-0 

17-5 

8 
10 

16-6 
16-6 

16-6 
15-5 

2 

17-7 

17-5 

Midn. 

16-6 

15-8 

4 

18-9 

17-7 

July  31st .     .     . 

2 

16-3 

15-5 

6 

18-3 

17-7 

4 

15-5 

15-5 

8 

16-1 

17-7 

6 

15-3 

14-7 

10 

16-1 

17-7 

■ 

8 

17-2 

14-7 

' 

Midn. 

15-8 

177    i 

10 

18-9 

12-5 

!  July  28th      .     . 

2 
4 

15-3 
15-0 

17-5 
16-6 

Near  Cork  Har-  \ 
hour      •     .     .] 

Noon. 

16-6 

12-2 

6 

15-5 

16-9 

2 

^ 

1 

8 

18-6 

16-6 

4 

18-3 

16-1 

10 

17-7 

16-6 

6 

16-1 

15-8 

Lat.    49°  59'  N.  \ 
Long.  12°22'W.  / 

Noon. 

19-4 

16-6 

8 
10 

14-4 
12-7 

14-4 
11-6 

2 

19-7 

16-9 

Midn. 

12-7 

iri 

i 

4 

18-3 

171 

August  1st    .     . 

2 

12-2 

; 

6 

16-6 

16-9 

4 

12-2 

1 

8 

15-5 

16-9 

6 

13-9 

10 

15-8 

15-5 

8 

16-6 

Midn. 

16-1 

16-6 

10 

17-5 

14-7 

July  29th      .     . 

2 

161 

17-2 

At  Queenstown . 

Noon. 

191 

14-7 

j 

4 

15-5 

17-7 

2 

18-9 

15-3 

I 

6 

15-8 

16-9 

4 

18-9 

15-8 

;   . 

8 

16-4 

16-9 

6 

10 

16-6 

16-6 

8 

13-9 

15-8 

Lat.     50°24'N.  ) 
Long.  ir42'W.  ] 

Noon. 

17-2 

16-3 

10 
Midn. 

12-2 
12-5 

15-0 
14-7 

2 

16-1 

16-3 

August  2nd  .     . 

2 

12-2 

14-4 

4 

17-7 

16-3 

4 

11-9  ■ 

15-0 

6 

17-7 

16-6 

6 

12-7 

15-5 

1   • 

8 

16-3 

17-2 

! 

•    8 

15-0 

15-3 

10 

16-1 

16-6 

10 

14-7 

Midn. 

16-1 

17-2 

At  Queenstown . 

Noon. 

15-5 

July  30th      .     . 

2 

16-1 

15-8 

2 

15-5 

^ 

4 

1  161 

15-8 

4 

16-4 

15-0 

6 

1  17-2 

15-8 

6 

15-3 

15-5 

8 

17-2 

15-8 

8 

13-9 

15-0 

! 

10 

17-2 

15-5 

i 
1 

10 

13-9 

15-0 

CHAP.  VII.] 


DEEP-SEA  TEMPERATURES. 


339 


Date  and  Position. 

1 

2 

emperature 
Sea-Surface. 

Date  and  Position. 

o 

It 
So 

II    \ 

f'  3 
a^     1 

&H 

^=3    I 

H 

^■s 

Deg. 

Deg.     ! 

Deg. 

Deg. 

Cent. 

Cent. 

Cent. 

Cent. 

August  2nd  .     . 

Midn. 

13-9 

13-9 

August  6th  .     . 

10 

17-7 

14-7 

August  3rd  .     . 

2 

15-3 

14-4 

At  Belfast     .     . 

Noon. 

18-3 

15-5 

4 

15-5 

14-1 

2 

6 

15-0 

13-9    1 

4 

18-9 

17-2 

8 

15-5 

13-9    ' 

■ 

6 

15-0 

10 

15-5 

14-1 

8 

130 

16-6 

Lat.  52°  22'  N.  ] 

] 

10 

11-1 

16-1 

Black  water,      > 

Noon. 

16-1 

13-6    ; 

Midn. 

10-0 

15-0 

Lat.  N.  11  miles.  ) 

August  7th   .     . 

2 

10-8 

15-5 

2 

16-2 

13-9 

4 

11-1 

15-5 

4 

18-3 

14-1 

6 

12-7 

15-5 

6 

17-2 

14-7 

8 

14-4 

15-5 

8 

15-5 

13-3 

10 

15-3 

15-5 

10 

14-4 

13-3 

At  Belfast     .     ; 

Noon. 

15-0 

15-0 

Midn. 

14-4 

13-3 

2" 

15-3 

15-5 

August  4th    .     . 

2 

13-9 

13-9 

4 

15-0 

15-5 

4 

13-3 

13-9 

6 

15-5 

6 

13-3 

12-7 

8 

8 

11-9 

12-5 

10 

14-7 

15-5 

10 

13-9 

12-2 

Midn. 

15-0 

14-7 

At  Copeland  Is-  \ 
land      .     .     •] 

Noon. 

14-4 

12-5 

August  8th   .     . 

2 
4 

13-9 
13-9 

15-0 
15-0 

2 

15-0 

13-9 

6 

4 

16-1 

16-1 

8 

15-0 

15-0 

6 

16-6 

15-8 

10 

15-5 

15-3 

8 

13-3 

At  Belfast     .     . 

Noon. 

17-2 

15-8 

10 

13-3 

15-0 

2 

20-8 

16-1 

Midn. 

11-1 

13-9 

4 

16-6 

15-8 

August  5th   .    . 

2 

11-1 

14-1 

6 

13-9 

15-5 

4 

10-5 

14-4 

8 

14-4 

15-8 

6 

12-7 

14-6 

10 

13-6 

15-8 

8 

15-3 

14-7 

Midn. 

13-9 

15-5 

10 

18-3 

15-0 

August  9th   .     . 

2 

13-3 

15-5 

At  Belfast     .     . 

Noon. 

16-9 

15-5 

4 

13-3 

15-5 

2 

17-4 

6 

13-3 

15-3 

4 

17-7 

16-4 

8 

13-3 

6 

12-8 

15-5 

10 

14-4 

15-5 

8 

At  Belfa,at     .     . 

Noon. 

15-0 

15-5 

10 

111 

15-0 

2 

16-1 

15-5 

Midn. 

10-0 

15-0 

4 

16-6 

15-5 

August  6th   .     . 

2 

10-5 

14-7 

1 

6 

14-4 

15-8 

4 

10-0 

14-4 

8 

11-4 

15-5 

6 

12-5 

14-1 

10 

10-5 

15-0 

8 

16-6 

14-4 

Midn. 

10-0 

14-4 

Z 

2 

340 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VII. 


Date  aufi  Position. 

§ 

fe 

1 

Date  and  Position. 

1     ■ 
1      % 

tl 

W 

i.^ 

W 

So 

tl 

H 

^=3 

■ 

Eh 

^■^ 

Deg. 

Deg. 

i 

Deg. 

Deg. 

Cent. 

Cent. 

Cent. 

C.nt. 

August  10th,     . 

2 

'  iri 

13-9 

August  13th.     . 

.    2 

12-5 

11-6 

4 

10-5 

14-7 

4 

12-7 

i2-2 

6 

10-5 

14-4 

6 

13-3 

l'l-6 

8 

11-4 

14-4 

8 

120 

1^-7 

10 

13-9 

10 

11-4 

11-6 

At  Belfast     .     . 

Noon. 

15-5 

15-0 

Midn. 

111 

12-2 

. 

2 

150 

August  14th .     . 

2 

11-6 

12-0 

4 

14-7 

4 

11-4 

11-4 

6 

12-7 

6 

11-4 

12-2 

.     8 

11-9 

15-0 

8 

13-3 

12-0 

10 

11-6 

14-4 

10 

12-7 

Midn. 

11-6 

13-9 

At  Stornoway    . 

Noon. 

15-5 

12-2 

1  August  11th.     . 

2 

10-5 

13-9 

2 

16-1 

12-5 

4 

11-7 

13-3 

4 

15-0 

127 

6 

12-2 

13-6 

6 

14-7 

1 

8 

13-3 

13-9 

8 

13-3 

12-2 

10 

14-4 

10 

13-3 

12-5 

111  Belfast  Lough 

Noon. 

14-4 

14-4 

Midn. 

12-7 

12-2 

2 

15-3 

12-2 

August  15th .     . 

2 

13-3 

12-2 

4 

15-0 

13-0 

4 

13-3 

12-2 

1 

6 

13-9 

12-2 

6 

13-3 

12-^ 

' 

8 

12-2 

12-2 

8 

13-9 

12-2 

10 

11-7 

11-7 

10 

13-9 

12-2 

Midn. 

12-0 

11-7 

At  Stornoway    . 

Noon. 

14-4 

12-2 

August  12th.     . 

2 

12-2 

12-2 

2 

15-8 

L2-5 

4 

iri 

11-7    1 

4 

16-1 

12-5 

6 

11-4 

12-0  ; 

6 

15-5 

12-6 

8 

13-3 

12-5    j 

8 

13-3 

12| 

10 

17-2 

127    j 

10 

12-7 

OoU      Island,      ] 
North,  3  miles  ( 

Noon. 

18-3 

12-5    ! 

1 

August  16th .     . 

Midn. 

2 

13-0 
12-7 

J^l 

2 

15-3 

13-3    ! 

4 

12-7 

12-1 

4 

14-4 

12-2    1 

6 

13-3 

12-2 

i 

6 

12-7 

12-2    1 

8. 

13-3  • 

12f 

1 
1 

8     i 

12-2 

12-0    i 

10 

13-6 

12t 

1 

10    1 
Midn. 

11-7 
12-0 

12-2    i 
12-2    j 

Lat.  59°  21'  N.   ^  ! 
Long.  6°  58'  W.  ]  i 

Noon. ' 

13-3 

1 

12-0 

August  13th.     .     1 

^ 

12-7 

11-6    1 

2     1 

130    j 

12-2    < 

4 

12-5 

11-6 

4     j 

13-3 

12-2 

6 

12-7 

120 

6 

13-3 

12-2. 

8 

12-5 

12-0 

1 

8 

12-7 

12^   \ 

10 

14-7 

11-6    1 

1 

10 

12-5 

12-2 

Shiant     Islands,  \ 
N.  N.  W.  6  miles  ^ 

Noon. 

13-3 

11-6 

August  17th.     . 

Midn. ' 

1 

12-2 
111 

12-2 
11-6 

CHAP.  VII. 


DEF.P-SEA  TEMPERATURES. 


341 


Date  and  Position. 


AuOTSt  17  th 


L;i*.  59°  3(5'  N. 
Long.  7°  12'  W. 


August  18th 


Lat.  60°  25'  N.   \ 
Long.  8°    9'  W.  ( 


August  19th . 


Lat.  60°  13'  N. 
Long.  6°  41'  W. 


August  20th 


O 

Temperature 
of  Sea-Sui-face. 

Deg. 
Cent. 

Deg.     i 

Cent. 

4 

12-2 

11-9 

6 

12-2 

11-9 

8 

12-2 

10 

13-9 

12-2 

!  Noon. 

13-9 

12-2    i 

2 

13-6 

11-9    \ 

4 

14-1 

11-9    1 

6 

130 

11-9    ' 

8 

12-5 

11-4    ^ 

10 

12-7 

IM    ; 

Midn. 

12-2 

11-1    ! 

2 

12-2 

10-5    1 

4 

12-2 

11-1    ll 

6 

12-7 

11-1 

8 

13-9 

11-4    :| 

10 

13-6 

10-8    \ 

Noon. 

13-6 

11-4 

2 

12-7 

iri 

4 

12-5 

10-8 

6 

12-2 

11-1     1 

8 

12-2 

11-1 

10 

12-2 

11-1 

Midn. 

12-2 

iri 

2 

12'2 

111 

4 

12-2 

111 

6 

12-7 

11-4 

8 

12-7 

11-4 

10 

13-3 

11-4 

Noon. 

12-7 

111 

2 

13-3 

11-1    1 

4 

13-9 

6 

12-7 

11-1 

8 

12-7 

iri   : 

10 

12-7 

111 

Midn. 

12-2 

10-5 

2 

12-2 

10-5 

4 

12-0 

lO'O 

6 

12-2 

10-8 

8 

12-5 

10-5 

10 

12-5 

10-3 

Date  and  Position. 


Lat.  60°  35'  N.   ] 
Long.  6°  41'  W.    ( 


August  21st 


Off     Sandu    in  / 
Fjeroe  Islands  ( 


August  22nd 


At  Thorshavn    . 


August  23rd 


At  Thorshavn 


3 
o 

2 

II 

Deg 

Cent. 

Deg. 

Cent. 

Noon. 

13-3 

11-4 

2 

12-7 

11-4 

4 

12-2 

11-6 

6 

9-4 

11-4 

8 

9-4 

10-5 

-  10 

9-7 

10-0 

Midn. 

lO'O 

9-4 

2 

10-0 

9-4 

4 

9-4 

9-4 

6 

10-0 

9-4 

8 

10-0 

10-0 

10 

13-6 

9-7 

Noon. 

13-3 

9-1 

2 

11-4 

8-8 

4 

11-7 

9-1 

6 

11-4 

91 

8 

10  5 

9-1 

10 

10-8 

9-4 

Midn. 

10-5 

9-4 

2 

10-5 

9-1 

4 

10-8 

9-4 

6 

HI 

9-1 

.8 

11-6 

9-4 

10 

12-7 

9-4 

Noon. 

14-4 

9-4 

2 

13-3 

9-7 

4 

12-2 

10-0 

6 

13-3 

9-7 

8 

10-5 

9-4 

10 

10-0 

9-4 

Midn. 

10-0 

9-4 

2 

9-4. 

9-4 

4 

6 

10-8 

9-4 

C\.  i 

8 
10 
Noon. 
2 
4 
6 


10-5 
12-7 
12-7 
12-7 
12-7 
12-2 
11-6 


9-4 
9-7 
9-7 
9-4 
9-4 
9-4 
91 


342 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VII. 


£ 

e| 

« 

s 

^ 

3;2 

Date  and  Position. 

^ 

l|  ; 

Date  and  Position. 

S 

II 

w 

to 

ll  1 

W 

§■■3 

05 

§!» 

H 

^^  1 

H 

^•s 

Deg. 

Deg. 

Deg. 

Deg. 

Cent. 

Cent. 

Cent. 

Cent. 

August  23rd      . 

10 

11-1 

9-4 

August  27th.     . 

8 

11-1 

11-4 

Midn. 

11-1 

9-1 

10 

11-6 

11-6 

August  24th .     . 

2 
4 

11-1 
11-1 

9-1 

9-4    1 

Lat.  60°  26'  N.    ) 
Long.  0°  15'  E.     ] 

Noon. 

12-5 

11-6 

6 

11-1 

9-4 

2 

13-3 

12-2 

8 

11-4 

9-1 

4 

12-2 

11-9 

10 

11-6 

9-1 

6 

11-1   • 

11-9 

About  10  miles  ) 
EastofHaalso    ] 

XT 

8 

iri 

12-2 

Noon. 

15-5 

9-1 

1 

10 

10-0 

12-2 

2 

12-0 

9-7 

Midn. 

9-4 

111 

4 

13-3 

10-0 

August  28th .     . 

2 

10-5 

11-6 

6 

11-1 

9-4 

4 

12-2 

11-6 

8 

11-1 

9-4 

6 

11-9 

11-9 

10 

10-5 

9-4 

8 

10-0 

111 

Midn. 

11-1 

9-4 

10 

10-0 

111 

August  25  th ,     . 

2 

11-6 

9-7 

At  Lerwick  .     . 

Noon. 

9-4 

111 

4 

11-6 

9-7 

2 

10-5 

111 

6 

12-5 

9-4 

4 

11-1 

111 

8 

12-5 

9-7 

6 

9-7 

111 

10 

12-5 

9-4 

8 

8-8 

111 

Lat.  61°  36'  N.  ) 
Long.  3°  45'  W.  ( 

Noon. 

12-2 

9-4 

10 
Midn. 

7-5 

7-2 

111 
111 

2 

12-2 

9-7 

August  29th .     . 

2 

7-2 

111 

4 

11-6 

9-4 

~ 

4 

7-7 

10-3 

6 

11-6 

9-4 

6 

7-7 

11-4 

8 

11-4 

9-7 

8 

9-4 

111 

10 

11-4 

9-1 

10 

9-7 

111 

Midn. 

12-0 

10-5 

At  Lerwick  .     . 

Noon. 

9-4 

111 

August  26th .     . 

2 

12-0 

11-1 

2 

9-4 

111 

4 

12-0 

11-1 

4 

9-4 

111 

6 

12-0 

iri 

6 

9-1 

111 

8 

12-0 

11-4 

8 

7-7 

111 

10 

12-2 

11-6 

10 

7-7 

10-8 

Lat.  61°  14'  N.  ) 
Long.  1°  58'  W.   ] 

Noon. 

12-7 

11-4 

August  30th .     . 

Midn. 
2 

8-9 
8-3 

10-8 
111 

2 

12-7 

11-4 

4 

77 

4 

11-6 

11-4 

' 

6 

8-3 

10-8 

6 

iri 

11-4 

1 

8 

10-3 

111 

8 

11-6 

11-4 

At  Lerwick  .     . 

10 

11-1 

111 

1 

10 

11-6 

iri 

Noon. 

11-6 

111 

Midn. 

11-4 

11-1 

I 

2 

12-7 

11-4 

1  August  27th .     . 

2 

11-1 

11-1 

4 

12-2 

111 

1 

4 

11-1 

11-1 

6 

J 
1 

6 

11-1 

iri 

8 

7-7 

111 

CHAP.  VII.] 


DEEP-SEA  TEMPERATURES. 


343 


Date  aud  Posiiion. 


August  30th . 
August  31st  . 

At  Lerwick   . 


September  1st 


Lat.  60°  27'  N. 
Long.  3°  11'  W. 


September  2nd 


i  Lat.  60°  29'  N. 
Long.  4°  38' W. 


September  3rd  . 


10 
Midn. 


Deg. 
Cent. 

7-2 
6-6 

7-2 

77 


6 

10-0 

8 

10-O,', 

10 

11-6    1 

Noon. 

12-2    i 

!       2 

13-6 

4 

11-1 

6 

10-5 

8 

11-1 

10 

10-8 

!  Midn. 

10-5 

2 

11-1 

4 

11-1    1 

6 

11-6    ; 

8 

11-6 

10 

11-1 

Noon. 

11-1 

2 

12-2 

4 

13-3 

6 

11-6 

8 

11-4 

10 

11-1 

Midn. 

11-1 

2 

10-8 

4 

10-8 

6 

11-1 

8 

11-1 

10 

11-1 

Noon. 

11-4 

2 

li'4 

4 

11-6    1 

6 

11-6    1 

8 

11-1 

10 

11-6 

Midn. 

ll'l 

2 

11-6 

4 

iri 

6 

11-1 

8 

11-6 

1^  ^ 


Deg. 
Cent. 
11-1 
11-1 
10-5 
10-5 
11-1 
111 
10-8 
11-1 
11-1 
11-1 
11-1 
11-1 
10-8 
11-1 
11-1 
11-6 
11-6 
11-6 
11-4 

11-6 

11-6 
11-4 
11-1 
11-1 
11-6 
11-6 
10-8 
10-5 
10-3 
10-3 
10-3 

10-0 

10-3 
10-5 
11-1 
11-1 
11-4 
11-6 
11-1 
11-1 
11-6 
11-6 


Date  und  Position. 


September  3rd 
Lat.  60°    3'  N. 
Long.  5°  10'  W. 


September  4th 


Lat.  59°  43'  N. 
Lono'.  6°  35'  W. 


September  5th 


I   Lat.  59°  38'  N. 
Long.  8°  25'  W. 


September  6th 


Lat.  59° 
Long.  9° 


37'  N. 
4' W. 


10 
Noon. 

2 

4 

6 

8 

10 

Midn. 

2 

4 

6 

8 
10 


Deg. 
Cent. 
13-0 


Deg. 
Cent. 
11-6 


12-7    I  11-6 


12-5 
12-2 
12-2 
12-5 
12-7 
12-7 
12-7 
13-3 
13-9 
13-9 
14-4 


Noon.  I  14-4 


2 

13-6 

4 

12-0 

6 

iri 

8 

11-1 

10 

10-8 

:  Midn. 

11-1 

1       2 

11-1 

i       4 

11-1 

6 

12-2 

8 

13-0 

10 

12-7 

Noon. 

12-7 

2 

130 

4 

12-7 

Noon. 

13-3 

2 

13-3 

4 

13-0 

6 

12-7 

8 

12-7 

10 

12-2 

Midn. 

12-5 

2 

12-2 

4 

12-5 

6 

12-7 

8 

12-7 

10 

13-3 

11-6 
11-6 
11-4 
11-4 
11-6 
12-2 
12-2 
12-2 
12-5 
12-5 
12-2 

12-2 

12-2 
12-2 
12-2 
11-6 
11-6 
12-0 
12-0 
11-6 
11-6 
11-6 
12-0 

12-2 

11-6 
11-6 
11-6 
11-6 
11-4 
11-4 
11-4 
11-4 
11-6 
11-6 
12-0 

12-2 


12-2 


344 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VII. 


« 

£ 

.    1 
«  S    ! 

£ 

ti 

5 

p 

p^ 

DiitP  and  Position. 

p 

%i 

Hi 

Date  and  Position. 

3 

<u 

^ 

P 

11  1 

S 

H 

-=5     ' 

t 

EH 

h| 

Deg. 

De.. 

Beff.   • 

Deg. 

Cent. 

Cent. 

Cent. 

Cent. 

September  6th  . 

6 

12-2 

12-0 

September  10th 

6 

14-4 

12-7 

8 

12-2 

12-2  ; 

■ 

8 

15-0 

12-7 

10 

12-2 

12-2 

10 

13-9 

12-7 

Midn. 

11-6 

11-6    i 

At  Stornoway    . 

Noon. 

16-3 

13-3 

September  7  th  . 

2 

11-4 

11-6    i 

2 

16-3 

13-9 

4 

10-5 

11-6 

4 

15-0 

13-6 

6 

10-5 

11-9    , 

6 

13-9 

13-3 

•   8 

12-2 

11-6 

8 

12-7 

13-3 

10 

14-7 

11-9 

10 

12-2 

13*0 

Lat.  59°  41'  N.    ( 
Long.  T  32'  W.    j 

Noon. 

15-5 

12-2 

September  11th 

Midn. 

2 

11-6 

iri 

12-7 
12-7 

2 

13-9 

12-2 

4 

11-1 

12-7 

4 

13-3 

12-2 

6 

11-1 

12-7 

6 

12-7 

12-2 

8 

11-1 

12-7 

8 

12-5 

12-5 

10 

13-9 

12-7 

10 

12-7 

12-2 

At  Stornoway    . 

Noon. 

15-3 

12-7 

Midn. 

12-2 

12-2 

2 

13-3 

12*2 

September  8th  . 

2 

12-2 

11-6 

4 

11-6 

12-7 

4 

12-7 

11-9 

6 

11-4 

12-7 

6 

12-7 

11-9 

8 

10-8 

12-7 

8 

13-6 

12-2 

10 

9-7 

12-2 

10 

15-0 

12-7 

Midn. 

9-4 

12-2 

Lat.  59°    7'  N.   ) 
Long.  6"  35'  W.   ] 

Noon. 

14-4 

12-7 

September  12th 

2 
4 

91 

8-9 

12-2 
12-2 

2 

15-3 

12-7 

6 

9-4 

12-2 

4 

15-5 

12-7 

8 

11-4 

12-2 

,. 

6 

13-3 

12-5 

10 

12-5 

12  2 

8 

13-3 

12-5 

At  Stornoway    . 

Noon. 

12-7 

12-2 

10 

13-3 

13-0 

2 

12-7 

12-5 

Midn. 

12-7 

13-0 

4 

12-7 

12-5 

September  9th  . 

2 

13-3 

12-7 

6 

111 

12-2 

4 

13-3 

12-7 

8 

10-5 

12-2 

6 

13-3 

12-7 

10 

10-0 

12-2 

8 

13-0 

12-7 

. 

Midn. 

11-1 

12-0 

10 

13-3 

12-7 

i  September  13th 

2 

10-0 

11-6 

At  Stornoway    . 

Noon. 

13-9 

12-7 

4 

91 

111 

2 

6 

11-1 

11-6 

4 

14-4 

12-7 

{ 

8 

11-1 

11-6 

6 

15-3 

12-7 

10 

13-0 

12-2 

8 
10 

15-5 
15-5 

12-7 
13-3 

i  In    Loch    Shell-  ) 
1       dag  .     .     .     .  } 

Noon. 

12-2 

12-0 

Midn. 

15-5 

12-7 

2 

14-1 

12-2 

September   10th 

2 

13-9 

12-7 

4 

14-4 

12-2 

4 

14-4 

12-7 

i 

n 

13-9 

12-2 

CHAP.  VIJ.] 


DEEP-SEA  TEMPERATURES. 


345 


Date  and  Position. 

o 

-2 

ll 

SOJ 

Ueg. 
Cent. 

Date  and  Position. 

o 

^■"3 

Temperature 
of  Sea-Surface. 

Deg. 

Cent. 

Deg. 
Cent. 

Deg. 
Cent. 

September  13fch 

8 

13-0 

12-2 

Abreast  of  Mull 

Noon. 

12-7 

13-0 

10 

12-2 

12-2 

2 

14-4 

13-3 

Midn. 

12-2 

12-2 

1 

4 

14-4 

13-3 

September    14th 

2 

11-6 

12-5 

■ 

6 

13-6 

12-7 

4 

12-2 

12-2 

8 

13-0 

13-3 

6 

12-5 

12-2 

10 

12-5 

13-0 

8 

12-2 

12-7 

Midn. 

12-0 

13-0 

10 

11-6 

12-7 

1 
1 

II.   Surface 

Tempe 

RATURE 

S   OBSER 

VED    DURING    THE 

Summer 

OF  187 

0. 

Date  and  Position 


July  6th 


Off  Scilly  Islands 


July  7  th 


Lat.  48°  49'  N.     \ 
Long.  9°  35'  W.  / 


s 

^ 

H 

Temperature 
of  Sea-Surface. 

Deg. 
Cent. 

Deg. 
Cent. 

2 

13-9 

12-2 

4 

14-4 

12-7 

6 

13-9 

12-5 

8 

14-7 

14-7 

10 

15-3 

13-6 

Noon. 

18-6 

18-3 

2 

19-7 

17-4 

4 

19-4 

18-3 

6 

18-9 

18-3 

8 

17-4 

17-7 

10 

16-6 

17-2 

Midn. 

16-1 

17-2 

2 

16-6 

16-6 

4 

16-6 

16-6 

6 

16-6 

16-6 

8 

16-9 

16-9 

10 

17-7 

16-4 

NOOD. 

18-3 

16-4 

2 

19-4 

16-4 

4 

18-9 

17-2 

Date  and  Position. 


July  7  th 
July  8th 


Lat.     48°31'N.  \ 
I'W.  ] 


Lonor.  10°  6' 


July  9  th 


£ 

£§ 

3 

B^ 

f^ 

ti  '-< 

rt  ^ 

^ 

z'< 

E  73 

M 

.go 

^cS 

S 

cj  CO 

H 

^=3 

Deg. 

Deg. 

Cent. 

Cent. 

6 

19-4 

16-4 

8 

17-2 

16-1 

10 

16-9 

16-4 

Midn. 

16-6 

16-4 

2 

16-6 

16-1 

4 

16-1 

16-1 

6 

16-9 

16-1 

8 

19-1 

16-2 

10 

20-8 

16-1 

Noon. 

19-6 

17-2 

2 

20-0 

17-5 

4 

18-6 

17-5 

6 

19-1 

17-5 

8 

17-7 

17-2 

10 

16-9 

17-2 

Midn. 

16-6 

16-9 

2 

16-1 

16-9 

4 

16-6 

16-6 

(' 

16-1 

16-6 

8 

16-1 

16-6 

346 

THE  DEPTHS  OF  THE  SEA. 

[chap.  ^ 

vu. 

i 

, 

If 

u 

ill 

2  3      !■' 

Date  and  Position. 

1 

|2 

11 

Date  and  Position. 

1 

So 

<u 

©CO 

<p 

<VX 

H 

H^ 

H 

^■s    i 

Deg. 

Deg. 

Deg. 

Deg. 

Cent. 

Cent. 

Cent. 

Cent. 

July  9tli  .     .     . 

10 

17-5 

16-6 

July  12th      .     . 

6 

17-9 

18-0 

Lat.  48°  26'  N.    ) 
Long.  9°  43' W.  ) 

Noon. 

17-5 

16-6 

8 
10 

16-6 
16-6 

18-0 
17-2 

2 

16-4 

16-6 

Midn. 

16-6 

17-7. 

4 

17-2 

16-6 

July  13th      .     . 

2 

17-2 

17-7 

6 

16-4 

16-6 

4 

17-5 

18-3 

8 

16-4 

16-1 

6 

17-7 

17-7* 

10 

16-6 

16-6 

8 

18-6 

17-5 

Midn. 

16-1 

16-4 

10 

18-9 

17-7 

July  10th      .     . 

2 
4 

16-1 
16-4 

16-6 
16-4 

Lat.  44°  59'  N.     ) 
Long.  9°  33'  W.    \ 

Noon. 

19-7 

18-2 

6 

16-6 

16-4 

2 

21-1 

18-9    ' 

8 

16-4 

16-4 

4 

22-5 

18-9 

10 

17-3 

16-6 

6 

21-1 

18-3 

Lat.  48°  28'  N.     ) 
Long.  9°  42' W.    i 

Noon. 

16-1 

16-6 

8 
10 

17-5 
17-5 

18-3 
18-0 

2 

17-7 

16-9 

Midn. 

17-2 

18-0 

4 

19-4 

16-9 

July  14th      .     . 

2 

17-7 

17-9 

6 

19-6 

16-6 

4 

17-2 

17-2 

8 

16-2 

16-6 

6 

16-9 

161 

10 

16-1 

16-1 

8 

18-3 

161 

Midn. 

16-1 

16-1 

10 

18-6 

15-5 

July  11th      .     . 

2 

16-1 

16-6 

Cape  Finisterre,  ) 

4 

16-4 

16-4 

E.  N.  N.         [ 

Noon. 

18-6 

15  8 

6 

16-4 

16-1 

10  miles  .     .  ) 

i 

8 

18-3 

16-1 

2 

18-6 

15-8    \ 

10 

18-6 

16-6 

4 

19-1 

15-8 

i  Lat.  48°    8'  N. 
Long.  9°  18'  W. 

Noon. 

18-6 

16-9 

6 

8 

17-5 
16-6 

15-8 
15-5 

2 

18-4 

17-2 

10 

16-6 

15-8 

4 

19-1 

17-3 

Midn. 

16-6 

161 

6 

17-3 

17-4 

July  15th      .     . 

2 

16-6 

161 

8 

16-6 

16-6 

4 

16-6 

16-6    : 

10 

17-2 

17-2 

6 

17-5 

16-4    ^ 

Midn. 

17-2 

17-7 

8 

18-3 

16-9  : 

July  12th      .     . 

2 

17-2 

177    I 

10 

18-9 

17-2   ' 

4 
6 

17-7 
17-4 

17-7 
18-0 

Lat.  42°  11'  N.     ) 
Long.  9°  13'  W.    ) 

Noon. 

20-0 

16-4    , 

8 

17-7 

18-3 

2 

22-3 

17-6 

10 

18-6 

18-0 

4 

21-2 

17-9 

Lat.  46°  26'  N.     ) 
Long.  9°  31'  W.    \ 

Noon. 

19-1 

18-2 

6 

8 

19-0 
17-9 

18-9    j 
18-9    j 

2 

19-4 

18-0 

10 

17-7 

18-9    i 

4 

17-7 

18-0 

Midn. 

18-9 

19-3    i 

CHAP.  VII.] 


DEEP-SEA  TEMPERATURES. 


347 


% 

il 

2 

s 

2§ 

3ig 

Date  and  Position. 

3 

O 

ii 

Is 

Date  and  Position. 

3 

o 

w 

is 

11 

s 

§!» 

am 

H 

^=0 

H 

^^ 

Deg. 

Deg. 

Deg. 

Deg. 

Cent. 

Cent. 

Cent. 

Cent. 

July  16th      .     . 

2 

15-5 

190 

July  19th      .     . 

2 

20-3 

18-0 

4 

17-2 

18-9 

4 

^0-3 

18-0 

6 

18-3 

17-9 

6 

19-5 

17-9 

8 

20-1 

19-4 

8 

19-4 

18-3 

10 

23-2 

17-9 

10 

18-9 

18-4 

At  Vigo    .     .     . 

Noon. 

23-6 

17-8 

Midn. 

18-6 

18-4 

' 

2 

23-6 

17-9 

July  20th      .     . 

2 

18-3 

18-3 

4 

23-4 

18-0 

4 

18-3 

18-3 

6 

21-6 

17-2 

' 

6 

19-4 

18-4 

8 

18-4 

16-1 

8 

24-4 

18-9 

10 

17-7 

16-6 

10 

23-3 

20-5 

July  nth      .     . 

Midn. 
2 

17-2 
17-7 

16-9 
16-1 

•Lat.  40°    0'  N.   ) 
Long.  9°  49' W.    \ 

Noon. 

24-4 

21-1 

4 

17-5 

16-5 

2 

25-5 

21-1 

6 

17-7 

16-6 

4 

26-3 

21-8 

8 

19-7 

16-4 

6 

23-3 

21-8 

10 

22-2 

16-1 

8 

21-6 

19-7 

At  Vigo    .     .     . 

Noon. 

32-2 

16-4 

10 

21-3 

20-8 

2 

26-6 

16-9 

Midn. 

21-3 

20-5 

4 

25-8 

15-8 

July  21st ..." 

2 

21-1 

20-5 

6 

22-5 

16-4 

4 

21-5 

19-7 

8 

20-8 

16-4 

6 

23-3 

18-9 

10 

20-0 

16-5 

8 

22-7 

19-4 

Midn. 

18-6 

16-2 

10 

24-5 

19-4 

July  18th      .     . 

2 

4 

18-3 
17-7 

16-4 

Lat.  39°  39'  N. 
Long.  9°  36'  W. 

Noon. 

25-5 

19-4 

6 

18-9 

16-1 

2 

25-0 

19-4 

8 

19-4 

16-6 

4 

23-9 

19-7 

10 

18-9 

6 

21-8 

19-4 

Lat.  41°  55'  N.    \ 
Long.  9"  30'  W.    ) 

Noon. 

19-1 

16-2 

8 
10 

20-1 
19-6 

19-4 
19-4 

2 

18-6 

16-3 

Midn. 

19-5 

19-1 

4 

18-9 

16-3 

July  22nd     .     . 

2 

19-4 

18-9 

6 

18-9 

16-4 

4 

18-9 

18-9    1 

8 

18-3 

16-6 

6 

20-0 

18-2 

10 

18-3 

16-6 

8 

21-2 

18-3 

Midn. 

17-7 

16-4 

10 

25-0 

19-4 

July  19th      .     . 

2 

4 

17-7 
17-7 

16-9 
16-9 

The      Farilhoes,  ) 
S.S.E.  5  miles  \ 

Noon. 

25-0 

18-9 

6 

19-4 

16  9 

2 

23-9 

19-1 

8 

20-8 

17-5 

4 

23-3 

20-5 

10 

20-1 

17-7 

6 

23-9 

19-4 

Lat.  40°  16'  N.   ) 
!  Long.  9°  33'  W.    ] 

Noon. 

20-3 

17-9 

1 

8 
10 

20-0 
18-9 

19-4 
18-3 

348 

THE  DEPTHS  OF  THE  SEA. 

CHAP. 

rii. 

I 
1 

1 

t 

£§ 

1 

1 

2 

Date  and  Position. 

o 

0 

So 

3:2 

is 

Date  and  Position. 

1        a 

l! 

ft:  o 

n 

il  ,. 

H 

^1 

H 

Deg. 

Deg. 

Deg. 

Deg. 

Cent. 

Cent. 

Cent. 

Cent. 

July  22nd     .     . 
July  23rd      .     . 

Midn. 
2 

191 
18-9 

18-0 
18-5 

Lat.  38°  17'  N.    ) 
Long.  9'  23'  W.    \ 

Noon. 

20-0 

18-9 

4 

19-3 

19-4 

2 

20-0 

19-1 

6 

20-5 

18-3 

4 

20-0 

19-1 

8 

23-3 

20-5 

6 

20-0 

19-4 

10 

247 

22-0 

8 

19-4 

191 

At  Lisbon     ,     . 

Noon. 

22-5 

21-1 

10 

20-0 

19-1 

2 

23-6 

19-1 

Midn. 

20-0 

19-0 

4 

21-6 

20-0 

July  27th      .     . 

2 

19-4 

19-1 

6 

23-0 

21-6 

4 

19-4 

19-1 

8 

20-5 

20-3 

6 

•19-4 

19-1 

10 

19-5 

19-1 

8 

20-0 

19-0 

Midn. 

20-1 

19-5 

10 

21-3 

20-0 

July  24th      .     . 

2 
4 

19-4 
19-4 

18-6 
20-5 

Lat.  37°  18'  N.    ) 
Long.  .9°  12' W.     i 

Noon. 

2ri 

20-3 

6 

20-1 

21-6 

2 

23*3 

20-5 

8 

20-8 

20-8 

4 

21-1 

20-6 

10 

21-2 

20-1 

6 

20-0 

207 

At  Lisbon     .     . 

Noon. 

24-1 

19-4 

8 

20-0 

20-5 

.2 

23-0 

20-5 

10 

19-4 

20-5    11 

4 

22-1 

20-1 

Midn. 

19-5 

20-8    1 

6 

22-2 

21-2 

July  2Sth      .     . 

2 

19-4 

2<)-3    ' 

8 

20-5 

21-4 

4 

19-4 

20-5 

10 

20-0 

20-0 

6 

19-1 

20-0 

Midn. 

19-4 

197 

8 

21-1 

21-1 

July  25th      .     . 

2 

19-1 

20-0 

10 

21-1 

212 

4 
6 

19-0 

20-3 

20-0 
191 

Lat.  36°  55'  N.    ) 
Long.  8°  44'  W.    \ 

Noon. 

21-8 

21-3 

8 

20-4 

19-4 

2 

21-6 

21-6 

10 

20-8 

19-1 

4 

21-6 

22-0 

La.t.  38=  10'  N.    ) 
Long.  9°  29'  W.    \ 

Noon. 

21-8 

19-4 

6 

8 

20-5 
18-9 

20-5 
20-0 

2 

21-1 

19-4 

10 

18-9 

19-4 

4 

20-8 

19-4 

Midn. 

18-6 

19-1 

6 

21-6 

19-4 

July  29th      .     . 

2 

18-3 

197 

8 

20-0 

18-0 

4 

18-3 

197 

10 

18-6 

177 

6 

21-1 

21-6 

Midn. 

18-0 

177 

8 

22-1 

22-4 

July  26th      .     . 

2 

18-3 

17-4 

10 

23-0 

22-2 

4 
6 

18-3 
19-1 

177 
191 

Lat.  36°  45'  N.    ) 
Long,  8°    8'  W.    i 

Noon. 

23-3 

22-5 

8 

19-4 

19-1 

2 

23-3 

22-3 

i 

10 

! 

20-3 

19-3 

4 

24-8 

231 

CHAP.  VII.] 

DEEP-SEA  TEMPERATURES. 

3 

49 

i     i 

II 

1      ^ 

£1 

Date  and  Position. 

SCO 

Date  and  Position. 

So 

II 

&  OS 
§02 

H 

^=o 

H 

o 

1 

De- 

Dey. 

1 

Deg. 

Des. 

1 

Cent 

Cent. 

Cent. 

Cent. 

July  29th      .     . 

1       6 

22-2 

22-5 

!  August  2nd  .     . 

8 

21-7 

23-2 

8 

21-1 

22-3 

j 

10 

22-8 

24-4 

10 
Midn. 

21-1 

20-5 

21-6 
21-6 

1  Lat.  36°  18'  N.    ) 
j  Long.  6°  45'  W. 

Noon. 

22-8 

23-0 

July  30th      .     . 

2 

20-3 

21-9 

1 

2 

22-5 

23-0 

1       4 

2()-5 

22-2 

4 

22-7 

23-0 

i       6 

20-5 

22-8 

6 

21-8 

22  8 

8 

22-4 

22-5 

8 

21-2 

22-2 

16 

23-3 

22-9 

1 

10 

21-3 

22-5 

Lat.  36°  27'  N.     ) 
Long  (f  39'  W.    \ 

Noon. 

23-9 

23-1 

August  3rd    .     . 

Midn. 

2 

21-1 
20-5 

22-2 
22-0 

2 

25-3 

24-1 

4 

20-5 

22-0 

4 

22-5 

24-1 

6 

21-8 

22-8 

6 

22-8 

24-2 

8 

23-7 

22-2 

8 

21-6 

24-1 

10 

23-3 

21-8 

10 
Midn. 

21-6 
21-5 

24-3 
24-3 

Lat.  35' 39'  N.    ) 
Long.  7"    4'  W.    \ 

Noon, 

216 

22-0 

July  31st .     .     . 

2 

21-1 

22-8 

2 

22-6 

22-2 

4 

21-9 

23-3 

4 

24-1 

22-2 

_ 

6 

21-9 

23-6 

6 

23-2 

22-2 

8 

22-5 

24-1 

8 

21-8 

22-2 

10 

24-5 

23-9 

10 

21-8 

22-0 

;     At  Cadiz  .     .     . 

Noon. 

25-2 

24-0 

Midn. 

22-5 

22-0 

.2 

25-1 

24-1 

August  4th    .     . 

2  • 

22-2 

22-2 

4 

24-0 

24-3 

4 

22-2 

22-2 

6 

24-0 

24-4 

6 

23-2 

22-2 

8 

23-4 

24-4 

8 

23-9 

22-2 

1 

10 

22-7 

24-1 

10 

24-4 

23-3 

August  1st    .     . 

Midn. 

2  . 

22-5 
22-3 

24-1 
23-9 

Lat.  35°  35'  N.    / 
Long.  6°  24'  W.    ) 

Noon. 

25-0 

233 

4 

21-6 

22-8 

2 

27-2 

23-4 

6 

22-5 

23-9 

4 

25-6 

23-3 

8 

24-4 

24-1 

6 

24-4 

23-3 

, 

10 

24-1 

24-4 

• 

8 

22-2 

21-8 

At  Cadiz  .     .     . 

Noon. 

23-9 

24-7 

10 

22-2 

22-0 

2 

23-6 

24-4 

Midn. 

22-2 

22-2 

4 

23-6 

24-4 

October  1st   .     . 

2 

17-4 

18-9 

6 

21-6 

23-3 

4 

17-8 

18-9 

! 

8 

21-6 

23-6 

6 

18-0 

18-0 

' 

10 

21-6 

23  9 

8 

19-4 

17-9 

Midn. 

21-8 

23-9 

10 

22-1 

21-5 

igust  2nd  .     .     . 

1 

2    ! 

4 

21-9 
21-3 

23-3 
23-0 

In      Strait       of  } 
G;i>raltar    .     .  i 

Noon. 

23-3 

22-2 

6 

21-6 

1 

23-3 

1 

2 

1 

24-1 

23-4 

350 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VII. 


Date  and  Position. 


October  1st  . 


October  2nd  . 


Lat.  36°  27'  N. 
Long.  8°  31'  W. 


October  3rd  . 


Lat.  38°  39'  N. 
Long.  9°  30'  W. 


October  4th  . 


Lat.  40°  57'  N. 
Long.  9°  29'  W. 


Z 

3 

i 

o 

1^ 

w 

1  o 

H 

Deg.     1 

Cent. 

4 

22-5 

6 

22-0 

8 

21-1 

10 

21-5 

Midn. 

20-8 

2 

21-1 

4 

22-3 

6 

22-6 

8 

24-7 

10 

24-7 

Noon. 

21-1 

2 

22-6 

4 

23-7 

6 

20-5 

8 

20-5 

10 

20-5 

Midn. 

20-5 

2 

20-0 

4 

19-4 

6 

19-1 

8 

18-3 

10 

18-6 

Noon. 

22-2 

2 

21-6 

4 

21-1 

6 

20-5 

8 

20-0 

10 

20-6 

Midn. 

20-5 

2 

20-8 

4 

20-6 

6 

21-1 

8 

21-6 

10 

22-2 

Noon. 

22-2 

2 

22-9 

4 

22-2 

6 

20-0    1 

8 

20-3    ! 

10 

18-9 

Midn. 

19-3 

g  5 


Deg. 
Cent. 
22-8 
22-6 
22-5 
22-2 
22-6 
22-8 
23-3 
22-9 
23-2 
23-3 

23-3 

23-4 
23-0 
22-5 
20-5 
20-8 
21-6 
21-1 
18-3 
20-5 
20-8 
20-5 

20-3 

20-5 
21-1 
20-6 
19-8 
20-3 
20-5 
21-1 
21-1 
21-1 
21-5 
21-0 

21-9 

21-1 
21-0 
20-5 
20-4 
19-4 
19-4 


Date  and  Position 


October  5  th  . 


Lat.  43°  33'  N. 
Long.  9°    3'  W. 


October  6th 


Lat.  46°  12'  N. 
LonjT.  8°    8'W. 


October  7th  . 


Lat.  48°  51'  N. 
Lons.  5°  54'  W. 


October  8th 


u 

o 

w 

Deg. 
Cent. 

2 

18-3 

4 

18-6 

6 

17-5 

8 

17-2    j 

10 

19-8    ! 

Noon. 

20-0    ! 

2 

20-5 

4 

19-8 

6 

18-3 

8 

17-9 

10 

18-5 

Midn. 

18-3 

2 

18-1 

4 

18-3 

6 

18-3 

8 

18-9 

10 

20-1 

Noon. 

20-0 

2 

19-5 

4 

19-3 

6 

18-3 

8 

18-3 

10 

17-9 

Midn. 

18-3 

2 

18-2 

4 

17-6 

6 

16-7    1 

8 

16-6 

10 

17-5 

Noon. 

17-5 

1       2 

17-7 

4 

17-7 

6 

15-3 

8 

14-7 

10 

15-3 

1  Midn. 

16-1 

2 

15-5    ' 

4 

15-0 

!       6 

15-6 

1       8 

16-1 

10 

16-6 

CHAP.  VII.] 


DEEP-SEA  TEMPERATURES. 


351 


^ 

ll 

Date  and  Position. 

o 

ll 

Date  and  Position. 

C3 
O 

1*^ 

1! 

H 

■^■s 

H 

^=o 

Deg. 

Deg. 

Deg. 

Deg. 

Cent. 

Cent. 

Cent. 

Cent. 

St.  Alban's  Hd.,  ) 

October  8th  .     . 

6 

15-0 

15-8 

Encrlish  Chan-  > 

Noon. 

18-6 

16-2 

8 

147 

157 

nel    .     .     .     .) 

10 

15-5 

15-6 

2 

19-5 

16-0 

At  Cowes      .     . 

Midn. 

15-3 

15-5 

4 

16-6 

15-8 

352 


THE  DEPTHS  OF  THE  SEA. 


[chap,  vji 


APPENDIX   B. 


Temperature  of  the  Sea  at  different  Depths  near  the  Eastern 
Margin  of  the  N'orth  Atlantic  Basin,  as  ascertained  hy  Serial 
and  hy  Bottom  Soundings. 


Serial  Soundings. 

Bottom  Soundings. 

i 

Tempe-  Tempe- 1  Tempe- ,  Tern  pe-  Tempe- 

Tempe- 

Tempe- 

Sta- 

Surface 

Bottom 

Depth. 

rature,  rature. 

rature    rature. 

rature. 

rature. 

rature. 

tion. 

Depth. 

Tempe- 

Tempe- 

Ser. 23. 

Ser.  42. 

Ser.  22.  Ser.  19. 

Ser.  20 

Se.r.  21. 

Ser.  38. 

No. 

rature. 

rature. 

Deg. 

Di'g. 

Deg. 

I>eg. 

Deg. 

Deg. 

Deg. 

Deg. 

Deg. 

Fma. 

Cent. 

Cent. 

Cent. 

Cent. 

Cent. 

Cent. 

Cent. 

Fms. 

Cent. 

Cent. 

0 

14-0 

17-0 

13-8 

12-6 

13-0 

13-4 

17-7 

50 

]l-8 

27 

34 

6 

35 

54 

:75 

90 
96 

13  1 
18-9 
12-2 
17-4 

9-0 

9-8 

100 

10-7 

100 

9  1 

10-6 

8 
24 

106 
109 

12-3 
14-3 

10-6 

8-0 

150 

... 

10-5 

7 

14 
18 

159 
173 
183 

11-8 
118 
11-8 

10-2 
9-7 
9-6 

200 

8-9 

10-2 

13 

208 

12-0 

9-7 

250 

10-1 

9-1 

8-9 

91 

9-0 

10-2 

4 

251 

12-0 

9-7 

300 

8-7 

9-7 

26 

345 

141 

8-1 

350 

9-5 

!    1 

370 

12-2 

9-4 

400 

8-6 

9-1 

15 

422 

11-2 

8-3 

450 

8-6 

45 

458 

15-9 

8-9 

500 

7*7 

8-5 

8-1 

8-1 

8-3 

8-6 

8-8 

i     40 

517 

17-4 

8-7 

550 

8-0 

1    39 

557 

17-2 

8-3 

600 

6 -9 

7-5 

1    41 

584 

17-4 

8-0 

630 

6-3 

1  - 

650 

6-8 

;    23& 

664 

14-1 

5-3 

700 

... 

6-4 

12 

3 

36 

670 
728 
725 

11-2 
12-5 
17-7 

5-9 
61 

75S 

... 

5-8 

5-5 

5-1 

5-3 

5-7 

5-2 

800 

5-5 

'      2 
16 

808 
816 

12-3 
11-6 

5-2 
4-1 

862 

... 

4-3 

44 

865 

16-2 

4-1 

louo 

... 

3-7 

3-6 

3-7 

3-6 

3-5 

43 
28 
17 

1207 
1215 
1230 

16-5 
14-2 
11-8 

31 
2-8 
3-2 

1250 

... 

... 

... 

... 

31 

3-2 

31 

29 

1264 

13-8 

2-7 

1300 

32 

13^0 

13-3 

3-0 

1360 

... 

3-0 

30 

1380 

13-3 

2-8 

1400 

! 

1443 

... 

2-7 

1476 

... 

... 

2-7 

! 

1500 

... 

2-9 

1 

1750 

... 

... 

... 

2-6 

1 

2090 

... 

... 

... 

2-4 

37 

2435 

18-6 

2-5 

CHAP.  VII.] 


DEEP-SEA  TEMPERATURES. 


353 


APPENDIX   C. 


iparative  Bates  of  Reduction  of  Temperature  with  Increase  of 
Depth  at  Three  Stations  in  dijferent  Latitudes,  all  of  them  on 
the  Eastern  Margin  of  the  Atlantic  Basin. 


Depth. 

Station  42. 
Lat.  49°  12'. 

1 

Station  23.              i 
Lat.  56°  13'.              { 

Station  87. 
Lat.  59°  35'. 

Tempera- 
ture. 

Difference 

Tempera- 
ture. 

1 
Difference.  ! 

Tempera- 
ture. 

Difference. 

Fathoms. 

Surface. 
100 
200 
300 
400 
500 
600 
V50 
767 

17°-  0  C. 
10-6 
10  -2 

9-7 

9-1 

8-1 

7  -5 

5  -8 

- 
6°-4C. 

0-4 

0-5 

0-6 

1  -0 

0-6 

1  -7 

14°-  0  C. 
9-  1 
8-9 
8-7 
;     8-6 
7-6 
6-9 

4°'  9  C.  1 
0-2 

0  -2 
0-  1 

1  -0 

0-7 

! 

11°-4C. 

8*5 
8-2 
8-1 
7-8 
7-3 
6-  1 

5-2 

2°-9C. 
0-3 
0-  1 
0  -3 

0  -5 

1  -2 

0-9 

A  A 


354 


THE  DEPTHS  OF  THE  SEA. 


[CHAF.  VTI. 


APPENDIX  D. 


Temperature  of 

the  A 

Sea  at  different  Depths  in  the  Warm  and 

Cold  Areas  lying  between  the  North 

of  Scotland,  the  Shetland. 

Islands,  and  the  Foeroe  Islands;  as 

ascertained  hy  Serial  and 

hy  Bottom  Soundings. 

1 

N.B. — The  Koman  numerals  indicate  the  'Lightning'  Temperature  Soundings, 

corrected  for  pressure. 

Warm  Area. 

Cold  Area.                                , 

Series  87. 

Sta- 

Depth. 

Sui-face 
Tempe- 

Bottom 
Tempe- 

Series 64. 

Ser.  52. 

Sta- 
tion. 

! 

Surface 

il 

Bottom  i  >• 
Tempe-  j 
rature. J 

'  '1 

tion. 

Depth.  Tempe- 

Depth. 

Tempe- 
rature. 

No. 

rature. 

rature. 

Depth. 

Tempe- 
rature 

Tempe- 
rature. 

No. 

j  rature. 

?'^; 

Deg. 

Deg. 

Deg. 

Beg. 

Deg. 

Deg.     1 

Fms. 

Cent. 

Fms. 

Cent. 

Cent. 

Fms. 

Cent 

Cent. 

Fms.     Cent. 

Cent. 

0 

11-4 

0 

9-8 

11-1 

50 

8-9 

73 

84 

11-5 

9-3 

50 

7-5 

9-1 

70 

QQ 

11-9 

7-3 

80 

92 

11-8 

9-6 

69 

67 

11-9 

6-5 

lOD 

8-5 

100 

7-2 

8-5 

68 

75 

11-4 

Q-Q 

71 

103 

11-6 

9-2 

61 

114 

10-2 

7-2 

81 

142 

11-8 

9-5 

62 

125 

9-7 

7-0 

150 

8-3 

84 

155 

12-3 

9-5 

150 

6-2 

8-0 

60 

167 

9-7 

6-8 

85 

190 

12-1 

92 

IX. 

170 

IM 

5  0 

200 

8-2 

74 

203 

11-4 

8-7 

200 
250 

4-2 
1-2 

7-5 

3-5 

300 

8-1 

3oa 

0-2 

--0-7 

63 

317 

9-4 

-1-0 

65 

345 

11-1 

-1-2     1 

76 

344 

10-2 

-1-3 

50 

355 

11-4 

7-9 

350 

-0-3 

54 

363 

11-4 

-0-3 

46 

374 

12-1 

7-7 

384 

-0-8 

400 

7-8 

89 

445 

11-7 

7-5 

400 
450 

-0-6 

-0-8 

86 

445 

12-0 

-1-1 

90 

458 

11-7 
12-0 

7-3 

53 

4S0 

11 -4. 

-0-7 

49 

475 

1    w 

7-4 

63 

rtoU 

493 

11  4t 

11 '2 

-1-1     ■:! 

500 

7-2 

500 

-1-1 

X. 

500 

10-5 

-0-7    ' 

XII. 

530 
642 

11-4 
12-2 

71 

6-5 

58 
VIII. 

540 
650 

I0-8 
11-6 

-0-7 

47 

-1-3 

XV. 

570 

11-1 

6-3 

550 

-1-1 

77 
59 

560 
680 

10-5 
11-5 

-1-3 
-1-3    1 

600 

6-1 

600 

-1-2 

1 

. 

XVIT. 
XIV. 

620 
650 

11-1 
11-6 

6-3 

5-8 

55 
57 

605 

11-4 

-13 

-0-8    i 

632 

111 

640 

-1-4 

■ 

700 

88 

705 

11-9 

5-9 

767 

5-2 

-T 

CHAP.  VII.] 


DEEP-SEA  TEMPERATURES. 


355 


APPENDIX   E. 


Intermediate  Bottom  Temperatures,  sliovnng  the  Intermixture  of 
Warm  and  Gold  Currents  on  the  Borders  of  the  Warm  and 
Cold  Areas. 


station. 
No. 

Depth. 

Surface 
Tempera- 
ture. 

Bottom 
Tempera- 
ture. 

station. 
No. 

Depth. 

Surface 
Tempera- 
ture. 

Bottom 
Tempera- 
ture. 

72 

Fathoms. 

76 

peg. 

Cent. 

11-3 

Deg. 
Cent. 

9-3 

75 

Fathoms. 

250 

Deg. 
Cent. 

10-8 

Deg. 
Cent. 
6-5 

79 

76 

11-2 

9-3 

78 

290 

11-2 

5-3 

73 

84 

11-5 

9-3 

i      82 

1 

312 

11-3 

51 

71 

103 

11-6 

9-2 

1      83 

362 

11-8 

3-0 

74 

203 

11-4 

8-7 

! 

66 

267 

11-4 

7-6 

15 

440 

10-9 

5-6 

A  a2 


CHAPTER  YIII. 

THE     GULF -STREAM. 

The  Range  of  the  '  Porcupine '  Temperature  Observations. — Low 
Temperatures  universal  at  great  Depths. — The  Difficulty  of  in- 
vestigating Ocean  Currents. — The  Doctrine  of  a  general  Oceanic 
Circulation  advocated  by  Captain  Maury  and  by  Dr.  Carpenter. — 
Opinion  expressed  by  Sir  John  Hers(;hel. — The  Origin  and  Exten- 
sion of  the  Gulf-stream. — The  Yiews  of  Captain  Maury;  of  Pro- 
fessor Buff ;  of  Dr.  Carpenter. — The  Gulf-stream  off  the  Coast  of 
North  America. — Professor  Bache's  '  Sections.' — The  Gulf-stream 
traced  bj'  the  Surface  Temperatures  of  the  North  Atlantic. — Mr. 
Findlay's  Views. — Dr.  Petermann's  Temperature  Charts. — Sources 
of  the  underlying  Cold  Water. — The  Arctic  Return  Currents. — 
Antarctic  Indraught. — Vertical  Distribution  of  Temperature  in 
the  North  Atlantic  Basin. 

All  the  temperature  investigations  carried  on  in 
H.M.S.S.  'Lightning'  and  'Porcupine'  during  the 
years  1868-69  and  1870,  with  the  exception  of  a 
series  of  observations  already  referred  to  taken  in 
the  Mediterranean  under  Dr.  Carpenter's  direction 
in  the  summer  of  1870,  were  included  within  an  area 
nearly  2,000  English  miles  in  length  by  250  in 
width,  extending  from  a  little  beyond  the  Fgeroe 
Islands,  lat.  62°  30'  N.,  to  the  Strait  of  Gibraltar, 
lat.  36°  N. 

The  greater  part  of  this  belt  may  be  described  as 


CHAP,  vul]  the  gulf-stream.  357 

the  eastern  border  of  the  North  Atlantic  fringing 
Western  Europe.  A  small  but  very  interesting  por- 
tion of  it  forms  the  channel  between  the  Fseroe 
Islands  and  the  North  of  Scotland,  one  of  the  chan- 
nels of  communication  between  the  North  Atlantic 
and  the  North  Sea ;  and  a  few  soundings  in  shallow 
water  to  the  east  of  Shetland  are  in  the  shallow 
North  Sea  basin.  It  is  evident,  therefore,  that  the 
greater  part  if  not  the  whole  of  this  belt  must  par- 
ticipate in  the  general  scheme  of  distribution  of 
temperature  in  the  North  Atlantic,  and  must  owe 
any  peculiarities  which  its  thermal  conditions  may 
present  to  some  very  general  cause. 

All  our  temperature  observations,  except  the  few 
taken  in  the  '  Lightning '  in  1868,  were  made  with 
thermometers  protected  from  pressure  on  Professor 
Miller's  plan,  and  the  thermometers  were  individually 
tested  by  Captain  Davis  at  pressures  rising  to  about 
three  'tons  to  the  square  inch  before  they  were  fur- 
nished to  the  vessel ;  they  were  also  more  than  once 
reduced  to  the  freezing-point  during  the  voyage  to 
ascertain  that  the  glass  had  been  in  no  w^ay  distorted. 
The  results  may  therefore  be  receivcfJ  with  absolute 
reliance  within  the  limits  of  error  of  observation, 
Avhich  were  reduced  to  a  minimum  by  the  care  of 
Captain  Calver. 

A  large  number  of  scattered  observations,  most 
of  which  have  unfortunately  been  made  with  instru- 
ments which  cannot  thoroughly  be  depended  upon 
for  accuracy  of  detail, — the  error,  however,  being 
probably  in  the  direction  of  excess  of  heat, — esta- 
blished the  singular  fact  that  although  the  tempera- 
ture of  the  surface  of  the  sea  in  equatorial  regions 


358 


THE  DEPTHS  OF  THE  SEA. 


[chap.  vm. 


may  reach  30°  C,  at  the  greatest  depths  both  in  the 
Atlantic  and  in  the  Pacific  the  temperature  is  not 
higher  than  from  2°  to  4°  C,  sometimes  falling  at 
great  depths  to  0°  C.  I  quote  from  Mr.  Prestwich's 
able  presidential  address  to  the  Geological  Society 
for  the  year  1871,  a  table  of  the  most  important  of 
these  earlier  obsei'vations  in  the  Atlantic  and  the 
Pacific  '} — 

Temperatures  of  the  Atlantic. 


Temperature. 

Latitude. 

Longitude. 

Depth 
in 

Observer  and  Date. 

Paths. 

Surface. 

Bottom. 

42°    O'N. 

34°  40'  W. 

780 

16-7°  C. 

6-6°  C. 

Chevalier. 

1837 

29     0 

34  50 

1400 

24-4 

6-1 

lh37 

7  21 

20  40 

505 

26-6 

2-2 

Lenz    .     . 

1832 

4  25 

26     6 

1006 

27-0 

3-2 

Tessan 

1841 

15     3S. 

23  14 

1200 

25-0 

4-1 

>>           * 

1841 

25  10 

7  59  E. 

886 

19-6 

3-0 

yy 

1841 

29  33 

10  57 

1051 

19-1 

2-0 

jj             • 

1841 

32  20 

43  50 

1074 

21-6 

2-4 

Lenz    .     . 

1832 

38  12 

54  SOW. 

333 

16-8 

3-0 

Tessan      . 

1841 

Temperatures  of  the  Pacific. 


Latitude. 

Longitude. 

Depth 
in 

Temperature. 

Observer  and  Date. 

Faths. 

Surface. 

Bottom. 

51°34'N. 

161°  41' E. 

957 

11-8°  C. 

2-5°  C. 

Tessan    .     .1832 

28  52 

173     9 

600 

25-5 

5-0 

Beechey  .     .  1828 

18     5 

174  10 

710 

24-7 

4-8 

.     .  1836 

4  32 

134  24  W. 

2045 

27-2 

1-7 

The'Bonite'  1837 

Equator. 

179  34 

1000 

30-0 

2-5 

Kotzebue     .  1824 

21  14  S. 

196     1 

916 

27-2 

2-2 

Lenz  .     .     .1834 

32  57 

176  42  E. 

782 

16-4 

5-4 

„     .     .     .  1834 

43  47 

80     6  W. 

1066 

13-0 

2-3 

Tessan     .     .  1841 

^  Address  delivered  at  the  Anniversary  Meeting  of  the  Geological 
Society  of  London  on  the  17th  of  February,  1871,  by  Joseph  Prest- 
wich,  F.E.S.     Pp.  36,  37. 


CHAP,  viii]  THE  GULF-STREAM.  359 

To  these  may  be  added  the  observations  of  Lieu- 
tenant S.  P.  Lee,  of  the  United  States  Coast  Survey, 
who,  in  August  1847,  recorded  a  temperature  of 
2°-7  C.  below  the  Gulf-stream  at  a  depth  of  1,000 
fathoms,  lat.  35°  26'  N.,  long.  73°  12'  W. ;  and  of 
Lieutenant  Dayman,  who  found  the  temperature  at 
1,000  fathoms  in  lat.  51°  N.  and  long.  40°  W.  to 
be  —  0°'4  C,  the  surface  temperature  being  12°* 5  C. 
These  results  are  fully  borne  out  by  the  recent 
determinations  of  Captain  Shortland,  H.N.,  who 
observed  a  temperature  of  2°-5  C.  in  deep  water  in 
the  Arabian  Sea  between  Aden  and  Eombay,^  by 
those  of  Commander  Chimmo,  R.N.,  and  Lieutenant 
Johnson,  11. N.,  who  found  at  various  points  in  the 
Atlantic  a  temperature  of  about  3°-9  C.  at  1,000 
fathoms,  and  a  slow  decrease  from  that  point  to 
2,270  fathoms,  where  the  temperature  registered  by 
unprotected  thermometers  was  Q°'Q  C,  reduced  by  the 
necessary  correction  for  pressure  to  about  1°*6  C.,^ 
and  finally  by  the  temperature  determinations  of  the 
'  Porcupine '  expeditions,  carefully  conducted  with 
protected  instruments,  but  not  carried  nearer  the 
tropics  than  the  latitude  of  the  Strait  of  Gibraltar ; 
and  they  appear  to  go  far  to  establish  a  nearly  uni- 
form temperature  for  abyssal  depths,  not  far  from 
the  freezing-point  of  fresh  water. 

As  it  was  evident  that  the  low  temperature  for 
deep  water  in  tropical  regions  could  not  be  acquired 

1  Sounding  Voyage  of  H.M.S.  '  Hydra,'  Captain  P.  F.  Shortland. 
London:  1869. 

^  Soundings  and  Temperatures  in  the  Gulf-stream.  By  Commander 
W.  Chimmo,  RN.  (Proceedings  of  the  Eoyal  Geographical  Society, 
vol.  xiii.) 


360  TEE  DEPTHS  OF  THE  SEA.  [chap.  vm. 

by  contact  with  the  surface  of  the  crust  of  the 
earth,  the  inevitable  conclusion  seems  to  have  been 
early  arrived  at  that,  if  such  temperatures  existed, 
they  must  be  due  to  a  general  oceanic  circulation, — 
to  surface  currents  of  vrarm  water  passing  towards 
the  poles,  and  compensating  counter- currents  of  cold 
water  from  the  poles  towards  the  equator.  Hum- 
boldt states  that  he  showed,  in  1812,  ''that  the  low 
temperature  of  the  tropical  seas  at  great  depths  could 
only  be  owing  to  currents  from  the  poles  to  the 
equator  "  ^ 

D'Aubuisson,  in  1819,  also  attributed  the  low 
temperature  of  the  sea  at  great  depths  at  or  near 
the  equator  to  the  flow  of  currents  from  the  poles.^ 

But  although  the  fact  of  the  existence  of  currents 
lowering  the  temperature  of  deep  water  in  equa- 
torial regions  was  admitted  by  various  authorities 
in  physical  geography,  little  light  was  thrown  upon 
the  causes  of  this  circulation.  Latterly,  the  whole 
subject  became  obscured  by  the  very  general  adop- 
tion of  the  doctrine  already  referred  to  of  a  perma- 
nent temperature  of  4°  C.  all  over  the  world  beyond 
a  certain  depth ;  and  it  was  not  until  the  publi- 
cation of  Captain  Maury's  fascinating  book  on  the 
*  Physical  Geography  of  the  Sea '  had  given  an  extra- 
ordinary stimulus  to  the  study  of  this  department 
of  science,  that  the  question  was  again  raised. 

It  was  natural  from  its  geographical  position,  and 
from  the  much  greater  opportunity  which  it  offered 
for  the  accumulation  of  the  almost  infinite  number 

1  Fragments  de  Geol.  et  de  Cliraatol.  Asiafc.,  1831. 

2  Trait6  de  Geognosie. — Quoted  in  the  Anniversary  Address  to  the 
Geological  Society  of  London,  1871. 


CHAP.  VIII.]  THE  G ULF-STREAM.  361 

of  data  required  for  the  consideration  of  such  sub- 
jects, that  the  basin  of  the  North  Atlantic  should 
be  selected  for  investigation,  more  particularly  as 
peculiarities  of  climate  seemed  there  to  be  limited  in 
space,  and  well  defined  and  even  extreme  in  character. 

It  seems  at  first  somewhat  singular  that  there 
should  be  any  room  for  question  as  to  the  causes, 
the  sources,  and  the  directions  of  the  ocean  currents 
which  traverse  the  ocean  in  our  immediate  neigh- 
bourhood, and  exercise  a  most  important  influence 
on  our  economy  and  well-being.  The  investigation 
is,  however,  one  of  singular  difficulty.  Some  currents 
are  palpable  enough,  going  at  a  rate  and  with  a  force 
which  make  it  easy  to  detect  them,  and  even  com- 
paratively easy  to  gauge  their  volume  and  define 
their  path;  but  it  seems  that  the  great  movements 
of  the  water  of  the  ocean,  those  which  produce  the 
most  important  results  in  the  transfer  of  tempera- 
ture and  the  modification  of  climate,  are  not  of  this 
character.  These  move  so  slowly  that  their  surface 
movement  is  constantly  masked  by  the  drift  of  vari- 
able winds,  and  they  thus  produce  no  sensible  effect 
upon  navigation. 

The  path  and  limits  of  such  bodies  of  moving 
water  can  only  be  determined  by  the  use  of  the 
thermometer.  The  equalizing  of  the  temperature 
of  bodies  of  water  in  contact  with  one  another  and 
differently  heated,  by  conduction,  diffusion,  and 
mixture,  is  however  so  slow,  that  we  usually  have 
but  little  difl&culty  in  distinguishing  currents  from 
different  sources. 

Up  to  the  present  time  little  had  been  done  in 
determining  the  depth  and  mass  of  currents  by  the 


362  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

thermometer,  and  uuder-eurrents  were  practically 
unknown ;  but  the  limits  of  surface  currents  had 
been  traced  with  considerable  precision  by  observa- 
tions of  the  temperature  of  the  surface  of  the  sea, 
even  when  the  movement  was  so  slow  as  not  to  be 
otherwise  perceptible.  The  amount  of  heat  received 
directly  from  the  sun  may  be  taken  approximately 
to  depend  upon  latitude  only,  and  this  heat  is  in 
addition  to  the  heat  of  the  surface  water  derived 
from  other  sources,  whatever  these  may  be.  Observa- 
tions of  surface  temperature  accordingly  give  us  the 
heat  derived  directly  from  the  sun  in  the  region,  and 
the  heat  derived  from  the  same  source  during  the 
passage  of  the  water  to  the  region,  in  addition  to  the 
original  heat  of  the  water ;  if,  therefore,  the  water  of 
any  region  be  derived  from — that  is  to  say,  form  part 
of — a  movement  of  water  from  a  polar  source,  and 
if  the  surface  water  of  another  area  on  the  same 
parallel  of  latitude  form  part  of  an  equatorial  current, 
although  in  that  particular  latitude  they  receive  in 
both  cases  the  same  amount  of  heat  from  the  sun, 
there  will  be  a  marked  difference  in  their  tempera- 
ture. To  take  an  extreme  case ;  the  mean  tem- 
perature of  the  sea  in  the  month  of  July  off  the 
Hebrides,  in  lat.  58°  N.,  in  the  path  of  the  Gulf- 
stream,  is  13°  C. ;  while  in  the  same  latitude  off  the 
coast  of  Labrador,  in  the  course  of  the  Labrador 
current,  it  is  4°  5  0. 

The  distribution  of  surface  temperature  in  the 
North  Atlantic  is  certainly  very  exceptional.  A 
glance  at  the  chart  PL  YII.,  representing  the  general 
distribution  of  heat  for  the  month  of  July,  shows 
that  the  isothermal  lines  for  that  month,  instead  of 


CH-VP.  viii]  THE  GULF-STREAM.  363 

tending  in  the  least  to  coincide  with  the  parallels 
of  latitude,  run  up  into  a  series  of  long  loops,  some 
of  them  continued  into  tlie  Arctic  Sea. 

The  temperature  of  the  bordering  land  is  not 
affected  to  any  perceptible  degree  by  direct  radia- 
tion from  the  sea ;  but  it  is  greatly  affected  by  the 
temperature  of  the  prevailing  winds.  Setting  aside 
the  still  more  important  point  of  the  equalization 
of  summer  and  winter  temperature,  the  mean  annual 
temperature  of  Bergen,  lat.  60°  24'  N.,  subject  to 
the  ameliorating  influence  of  the  jjrevailing  south- 
west wind  blowing  over  the  temperate  water  of  the 
North  Atlantic,  is  6°-7  C. ;  while  that  of  Tobolsk, 
lat.  58°  13'   N.,  is  -  2°  4  C. 

But  the  temperature  of  the  Xorth  Atlantic  and 
its  bordering  lands  is  not  only  raised  above  that 
of  places  on  the  same  parallel  of  latitude  having  a 
'  continental '  climate,  but  it  is  greatly  higher  than 
that  of  places  apparently  similarly  circumstanced  to 
itself  in  the  southern  hemisphere.  Thus  the  mean 
annual  temperature  of  the  Pseroe  Islands,  lat.  62°  2'N., 
is  7°'l  C,  nearly  equal  to  that  of  the  Ealkland  Islands, 
lat.  52°  S.,  which  is  8°'2  C. ;  and  the  temperature  of 
Dublin,  lat.  53°  21'  K,  is  9°-6  C,  while  that  of  Port 
Pamine,  lat.  53°  8'  S.,  is  5°-3  C.  Again,  the  high 
temperature  of  the  North  Atlantic  is  not  equally 
distributed,  but  is  very  marked  in  its  determination 
to  the  north-east  coast.  Thus  the  mean  annual 
temperature  of  Halifax  (Nova  Scotia),  lat.  44°  39'  N., 
is  6°-2  C,  while  that  of  Dublin,  lat.  53°  21'  N., 
is  9° '6  C. ;  and  the  temperature  of  Boston  (Mass.), 
lat.  42°  21'  N.,  is  exactly  the  same  as  that  of 
Dublin. 


364  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

This  remarkable  diversion  of  the  isothermal  lines 

from   their   normal    direction    is  admittedly   caused 

t/ 

by  ocean  currents  affecting  the  temperature  of  the 
surface  while  conveying  the  warm  tropical  water 
towards  the  polar  regions,  whence  there  is  a  con- 
stant counterflow  of  cold  water  beneath  to  supply 
its  place. 

We  thus  arrive  at  the  well-known  result  that  the 
temperature  of  the  sea  bathing  the  north-eastern 
shores  of  the  North  Atlantic  is  raised  greatly  above 
its  normal  point  by  currents  involving  an  inter- 
change of  tropical  and  polar  water;  and  that  the 
lands  bordering  on  the  North  Atlantic  participate 
in  this  amelioration  of  climate  by  the  heat  imparted 
by  the  water  to  their  prevailing  winds. 

This  phenomenon  is  not  confined  to  the  North 
Atlantic,  although  from  its  peculiar  configuration 
and  relation  to  the  land  that  ocean  presents  the 
most  marked  example.  A  corresponding  series  of 
loops,  not  so  well  defined,  passes  southwards  along 
the  east  coast  of  South  America,  and  a  very  marked 
series  occupies  the  north-eastern  angle  of  the  Pacific 
off  the  Aleutian  Islands  and  the  coast  of  California. 

Two  principal  views  have  been  held  as  to  the 
causes  of  the  currents  in  the  North  Atlantic.  One  of 
these,  which  appears  to  have  been  first  advanced  in 
a  definite  form  by  Captain  Maury,  and  which  has 
received  some  vague  support  from  Professor  Buff,  is 
that  the  great  currents,  and  counter-currents  of  warm 
and  cold  water  are  due  to  a  circulation  in  the  watery 
shell  of  the  globe,  comparable  to  the  circulation  of 
the  atmosphere, — that  is  to  say,  caused  by  tropical 
heat  and  evaporation,  and  arctic  cold. 


CHAP.  VIII.]  THE  GULF-STREAM.  365 

It  is  not  easy  to  understand  Captain  Maury's  view. 
He  traces  all  ocean  currents  to  differences  in  specific 
gravity.  He  says  :  *'  If  we  except  the  tides,  and  the 
partial  currents  of  the  sea,  such  as  those  that  may  be 
created  by  the  wind,  we  may  lay  it  down  as  a  rule 
that  all  the  currents  of  the  ocean  owe  their  origin  to 
the  differences  of  specific  gravity  between  sea-water 
at  one  place  and  sea-water  at  another ;  for  wherever 
there  is  such  a  difference,  whether  it  be  owing  to  dif- 
ference of  temperature  or  to  difference  of  saltness, 
&c.,  it  is  a  difference  that  disturbs  equilibrium,  and 
currents  are  the  consequence."^  These  differences 
in  specific  gravity  he  attributes  to  two  principal 
causes ;  differences  in  temperature,  and  excess  of  salts 
produced  by  evaporation.  Captain  Maury  explains 
his  views  as  to  the  first  of  these  causes  by  an  illustra- 
tion. "  Let  us  now  suppose  that  all  the  water  within 
the  tropics  to  the  depth  of  one  hundred  fathoms  sud- 
denly becomes  oil.  The  aqueous  equilibrium  of  the 
planet  would  thereby  be  disturbed,  and  a  general 
system  of  currents  and  counter-currents  would  be 
immediately  commenced,  the  oil  in  an  unbroken  sheet 
on  the  surface  running  towards  the  poles,  and  the 
water  as  an  under-current  towards  the  equator.  The 
oil  is  supposed,  as  it  reaches  the  polar  basin,  to  be  re- 
converted into  water,  and  the  water  to  become  oil  as 
it  crosses  Cancer  and  Capricorn,  rising  to  the  surface 
in  intertropical  regions,  and  returning  as  before." 
"  Now,  do  not  the  cold  water  of  the  north,  and  the 
warm  water  of  the  gulf  made  specifically  lighter  by 
tropical  heat,  and  which  we  see  actually  presenting 

^  The  Physical  Geography  of  the  Sea,  and  its  Meteorology.     By 
M.  T.  Maury,  LL.D. 


366  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

such  a  system  of  counter-currents,  hold  at  least,  in 
some  degree,  the  relation  of  the  supposed  water  and 
oil."^ 

u  There  can  be  no  doubt  that  Maury  concludes 
that  the  waters  in  intertropical  regions  are  expanded 
by  heat,  and  those  in  polar  regions  are  contracted  by 
cold,  and  that  this  tends  to  produce  a  surface-current 
from  the  equator  to  the  poles,  and  an  under-current 
from  the  poles  to  the  equator."^ 

With  regard  to  increased  specific  gravity  produced 
by  excess  of  salt,  Captain  Maury  says, — 

"  The  brine  of  the  ocean  is  the  ley  of  the  earth. 
From  it  the  sea  derives  dynamical  power,  and  its  cur- 
rents their  main  strength."^  '' One  of  the  purposes 
which  in  the  grand  design  it  was  probably  intended 
to  accomplish  by  leaving  the  sea  salt  and  not  fresh, 
was  to  impart  to  its  waters  the  forces  and  powers 
necessary  to  make  their  circulation  complete."*  "  In 
the  present  state  of  our  knowledge  concerning  this 
wonderful  phenomenon  (for  the  Gulf- stream  is  one 
of  the  most  marvellous  things  in  the  ocean),  we  can 
do  little  more  than  conjecture.  But  we  have  the 
causes  in  operation,  which  we  may  safely  assume 
are  among  those  concerned  in  producing  the  Gulf- 
stream.  One  of  these  is  the  increased  saltness  of 
its  water  after  the  trade-winds  have  been  supplied 
with  vapour  from  it,  be  it  much  or  little  ;  and  the 
other  is  the  diminished  quantum  of  salt  which  the 

^  Captain  Maury,  op.  cit. 

2  On  Ocean  Currents.  Part  III.  On  the  Physical  Cause  of  Ocean 
Currents.  By  James  Croll,  of  the  Geological  Survey  of  Scotland. 
(Philosophical  Magazine,  October  1870.) 

^  Captain  Maury,  op.  cit.  ^  w^i^^ 


CHAP.  VIII.]  WE  GULF-STREAM.  367 

Baltic  and  the  northern  seas  contain."  ^  "  Now,  here 
we  have  on  one  side  the  Caribbean  Sea  and  Gulf  of 
Mexico  with  their  waters  of  brine ;  on  the  other, 
the  great  Polar  Basin,  the  Baltic,  and  the  North  Sea, 
the  two  latter  with  waters  that  are  but  little  more 
than  brackish.  In  one  set  of  these  sea-basins  the 
water  is  heavy,  in  the  other  it  is  light.  Between 
them  the  ocean  intervenes ;  but  water  is  bound  to 
seek  and  to  maintain  its  level ;  and  here,  therefore, 
we  unmask  one  of  the  agents  concerned  in  causing 
the  Gulf-stream."  2 

As  Mr.  James  CroU  has  very  clearly  pointed  out. 
Captain  Maury's  two  causes  tend  to  neutralize  each 
other. 

"  Now  it  is  perfectly  obvious  that  if  diflPerence  in 
saltness  is  to  co-operate  with  difference  in  tempera- 
ture in  the  production  of  ocean  currents,  the  saltest 
waters,  and  consequently  the  densest,  must  be  in 
the  polar  regions;  and  the  waters  least  salt,  and 
consequently  lightest,  must  be  in  equatorial  and  in- 
tertropical regions.  Were  the  saltest  water  at  the 
equator  and  the  freshest  at  the  poles,  it  would  tend 
to  neutralize  the  effect  due  to  heat,  and,  instead  of 
producing  a  current,  would  simply  tend  to  prevent 
the  existence  of  the  currents  which  otherwise  would 
result  from  difference  of  temperature."  '*  According 
to  both  theories  it  is  the  differences  of  density  be- 
tween the  equatorial  and  polar  waters  that  gives  rise 
to  currents ;  but  according  to  the  one  theory,  the 
equatorial  waters  are  lighter  than  the  polar,  whilst 
according  to  the  other  theory  they  are  heavier  than 
the  polar.     Either  the  one  theory  or  the  other  may 

Captain  Maury,  op.  cit.  ^  Ibid. 


368  THE  DEPTHS  OF  THE  SEA.  [chap.  yiii. 

be  true,  or  neither;  but  it  is  logically  impossible  that 
both  of  these  can,  for  the  simple  reason  that  the 
waters  of  the  equator  cannot  at  the  same  time  be 
both  lighter  and  heavier  than  the  water  at  the  poles/' 
'*  So  long  as  the  two  causes  continue  in  action,  no 
current  can  arise  unless  the  energy  of  the  one  cause 
should  happen  to  exceed  that  of  the  other,  and  even 
then  a  current  will  only  exist  to  the  extent  by 
which  the  strength  of  the  one  exceeds  that  of  the 
other."  1 

It  seems  scarcely  necessary  to  enter  further  into 
detail  in  reference  to  Captain  Maury's  theory  of  ocean 
currents,  which  is  really  chiefly  remarkable  for  its 
ambiguity,  and  for  the  pleasant  popular  style  in 
which  it  is  advocated;  since  my  friend  and  col- 
league Dr.  Carpenter  has  latterly  brought  into  great 
prominence  what  appears  to  be  a  modification  of  the 
same  view,  put  in  a  more  definite  form. 

Professor  Buff,  in  his  excellent  little  volume  on  the 
Physics  of  the  Earth,  speaking  of  the  layer  of  cold 
water  derived  from  the  Arctic  seas  which  underlies 
the  tropical  ocean,  and  its  method  of  transport,  says  : 
"  The  following  well-known  experiment  clearly  illus- 
trates the  manner  of  the  movement.  A  glass  vessel 
is  to  be  filled  with  water  with  which  some  powder 
has  been  mixed,  and  is  then  to  be  heated  at  bottom. 
You  will  soon  see,  from  the  motion  of  the  particles 
of  powder,  that  currents  are  set  up  in  opposite  direc- 
tions through  the  water.  Warm  water  rises  from  the 
bottom,  up  through  the  middle  of  the  vessel,  and 
spreads  over  the  surface ;  while  the  colder,  and  there- 
fore heavier  liquid,  falls  down  at   the  sides  of  the 

^  James  Croll,  op.  cit. 


CHAP,  viri.]  THE  GULF-STREAM.  369 

glass.  Currents  like  these  must  arise  in  all  water- 
basins,  and  even  in  the  oceans  if  different  parts  of 
their  surface  are  unequally  heated."^ 

This  is  of  course  a  common  class-experiment  illus- 
trating convection.  It  is  evidently  impossible  that 
movements  of  ocean  water  can  be  produced  in  this 
way,  for  it  is  well  known  that  everywhere,  except 
under  certain  exceptional  circumstances  in  the  polar 
basin,  the  temperature  of  the  sea  decreases  i'rom  the 
surface  to  a  minimum  at  the  bottom,  and  tropical 
heat  is  applied  at  the  surface  only.  It  is  singular 
that  this  irrelevant  illustration  should  have  been 
introduced  by  Professor  Buff;  for  his  account  of  the 
origin  and  extension  of  the  Gulf-stream,  which  may 
be  taken  as  the  type  and  exponent  of  ocean  currents, 
is  quite  consistent  with  the  commonly  received 
opinions. 

On  working  up  the  temperature  results  of  the 
*  Porcupine '  expedition  of  1869,  Dr.  Carpenter  satis- 
fied himself  that  the  mass  of  comparatively  warm 
water,  800  fathoms  deep,  which  we  had  established  as 
existing,  and  probably  moving  in  a  north-easterly 
direction,  along  the  west  coasts  of  Britain  and  the 
Lusitanian  peninsula,  could  not  be  an  extension  of 
the  Gulf-stream,  but  must  be  due  to  a  general  circu- 
lation of  the  waters  of  the  ocean  comparable  with 
the  circulation  of  the  atmosphere. 

"  The  influence  of  the  Gulf-stream  proper  (meaning 

^  Familiar  Letters  on  the  Physics  of  the  Earth ;  treating  of  the 
chief  Movements  of  the  Land,  the  Water,  and  the  Air,  and  the  Forces 
that  give  rise  to  them.  By  Henry  Buff,  Professor  of  Physics  in  the 
University  of  Giessen.  Edited  hy  A.  W.  Hofmann,  Ph.D.,  F.E.S. 
London:   185L 

B    B 


370  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

by  this  the  body  of  superheated  water  which  issues 
through  the  'narrows*  from  the  Gulf  of  Mexico),  if 
it  reaches  this  locality  at  all—  which  is  very  doubtful 
— could  only  affect  the  most  superficial  stratum ;  and 
the  same  may  be  said  of  the  surface- drift  caused 
by  the  prevalence  of  south-westerly  winds,  to  which 
some  have  attributed  the  phenomena  usually  ac- 
counted for  by  the  extension  of  the  Gulf-stream  to 
these  regions.  And  the  presence  of  the  body  of 
water  which  lies  between  100  and  600  fathoms  depth, 
and  the  range  of  whose  temperature  is  from  48° 
(8°-85  C.)  to  42°  (5°'5  C),  can  scarcely  be  accounted 
for  on  any  other  hypothesis  than  that  of  a  great 
general  movement  of  equatorial  water  towards  the 
polar  area,  of  which  movement  the  Gulf-stream  con- 
stitutes a  peculiar  case,  modified  by  local  conditions. 
In  like  manner  the  arctic  stream  which  underlies 
the  warm  superficial  strata  in  our  cold  area,  con- 
stitutes a  peculiar  case,  modified  by  the  local  condi- 
tions, to  be  presently  explained,  of  a  great  general 
movement  of  polar  water  towards  the  equatorial 
area,  which  depresses  the  temperature  of  the  deepest 
parts  of  the  great  oceanic  basins  nearly  to  the 
freezing-point."  ^ 

At  first  Dr.  Carpenter  appears  to  have  regarded 
this  oceanic  circulation  as  a  case  of  simple  convection. 
"To  what,  then,  is  the  north-east  movement  of  the 
warm  upper  stratum  of  the  North  Atlantic  attri- 
butable ?  I  have  attempted  to  show  that  it  is  part 
of  a  general  interchange  between  polar  and  equa- 
torial  waters,  which  is  quite  independent  of  any  such 

1  A  Lecture  delivered  at  the  Royal  Institution,  abstracted  with 
the  Author's  signature  in  Nature,  vol.  i.  p.  488  (March  10th,  1870). 


CHAP.  VIII.]  THE  GULF-STREAM.  37  [ 

local  accidents  as  those  which  produce  the  Gulf- 
stream  proper,  and  which  gives  movement  to  a  much 
larger  and  deeper  body  of  water  than  the  latter  can 
affect.  The  evidence  of  such  an  interchange  is  two- 
fold— that  of  physical  theory,  and  that  of  actual 
observation.  Such  a  movement  must  take  place,  as 
was  long  since  pointed  out  by  Professor  Buff,  when- 
ever an  extended  body  of  water  is  heated  at  one  part 
and  cooled  at  another  ;  it  is  made  use  of  in  the  warm- 
ing of  buildings  by  the  hot- water  apparatus,  and  it 
was  admirably  displayed  at  the  Royal  Institution  a 
few  months  since  in  the  following  experiment  kindly 
prepared  for  me  by  Dr.  Odling."  Dr.  Carpenter 
then  repeats  Professor  Buff's  convection  experiment, 
the  heat  being  applied  by  a  steam  jet  introduced 
vertically  at  one  end  of  a  narrow  glass  trough  while 
a  block  of  ice  was  wedged  into  the  other  end. 
"Thus  a  circulation  was  shown  to  be  maintained 
in  the  trough  by  the  application  of  heat  at  one  of  its 
extremities  and  of  cold  at  the  other,  the  heated  water 
flowing  along  the  surface  from  the  warm  to  the  cold 
end,  and  the  cooled  water  flowing  along  the  bottom 
from  the  cold  to  the  warm  end ;  just  as  it  has  been 
maintained  that  equatorial  water  streams  on  the 
surface  towards  the  poles,  and  that  polar  water 
returns  along  the  bottom  towards  the  equator,  if 
the  movement  be  not  interfered  with  by  interposed 
obstacles,  or  prevented  by  antagonistic  currents 
arising  from  local  peculiarities."^ 

That  such  a  movement  cannot  take  place  on  this 
hypothesis  has  been  already   shown  ;   and  Dr.  Car- 

^  The  Gulf-stream.     A  letter  from  Dr.  Carpenter  to  the  Editor  of 
NaUire,  dated  Gibraltar,  August  11th,  1870.     {Nature,  vol.  ii.  p.  334.) 

BB2 


372  THE  DEPTHS  OF  THE  SEA.  [chap.  viti. 

penter  in  a  lecture  to  tlie  Royal  Geographical 
Society,  in  an  illustration  drawn  from  two  supposed 
basins,  one  under  equatorial  conditions  and  the  other 
under  polar,  connected  by  a  strait,^  says  :  "The  effect 
of  surface-^^^^  upon  tlie  water  of  the  tropical  basin 
will  be  for  the  most  part  limited  to  its  uppermost 
stratum,  and  may  here  be  practically  disregarded. 
But  the  effect  of  surface-cold  upon  the  water  of  the 
polar  basin  will  be  to  reduce  the  temperature  of  its 
whole  mass  below  the  freezing-point  of  fresh  water, 
the  surface  stratum  sinking  as  it  is  cooled,  by  virtue 
of  its  diminished  bulk  and  increased  density,  and  being 
replaced  by  water  not  yet  cooled  to  the  same  degree. 
The  warmer  water  wdll  not  come  up  from  below,  but 
will  be  drawn  into  the  basin  from  the  surface  of  the 
surrounding  area ;  and  since  what  is  thus  drawn 
away  must  be  supplied  from  a  yet  greater  distance, 
the  continual  cooling  of  the  surface  stratum  in  the 
polar  basin  will  cause  a  'set'  of  water  towards  it  to 
be  propagated  backwards  through  the  whole  inter- 
vening ocean  in  connection  with  it,  until  it  reaches 
the  tropical  area."  And  further  on  in  the  same 
address :  "  It  is  seen  that  the  application  of  cold  at 
the  surface  is  precisely  equivalent  as  a  moving  power 
to  that  application  of  heat  at  the  bottom  by  which 
'  the  circulation  of  water  is  sustained  in  every  heating 
apparatus  that  makes  use  of  it."  No  doubt  the 
application  of  cold  to  the  surface  of  a  mass  of  water 
previously  at  the  same  temperature  throughout,  would 

1  On  the  Gibraltar  Current,  the  Gulf-stream,  and  the  general 
Oceanic  Circulation.  By  Dr.  W.  B.  Carpenter,  F.E.S.  Reprinted 
from  the  Proceedings  of  the  Royal  Geographical  Society  of  London, 
1870. 


CHAP.  viii.J  THE  GULF-STREAM.  373 

have  the  same  effect  as  the  application  of  heat  to 
the  bottom,  and  in  either  case  we  should  have  an 
instance  of  simple  convection,  the  warmer  under- 
water rising  through  a  colder  upper  layer;  but 
that  is  not  what  we  have  in  the  polar  sea ;  for  the 
temperature  of  the  arctic  sea  gradually  sinks  from 
a  few  fathoms  beneath  the  surface  to  a  minimum 
temperature,  and  consequent  maximum  density,  at 
the  bottom.  Therefore  in  this  case  the  application 
of  cold  at  the  surface  is  not  equivalent  to  the  appli- 
cation of  heat  to  the  bottom  in  a  hot- water  heating 
apparatus,  and  Dr.  Carpenter  has  shown  that  he  is 
aware  of  this  by  requiring  the  backward  propagation 
of  a  surface-iiVivr&ni, 

That  a  certain  efiPect  in  increase  of  specific  gravity 
must  be  produced  by  the  cooling  of  the  surface  film 
of  the  arctic  ocean  there  seems  to  be  little  doubt ; 
but  the  area  of  maximum  eff^ect  is  very  limited,  and 
during  the  long  arctic  winter  the  greater  part  of  that 
area  is  protected  by  a  thick  layer  of  ice,  one  of  the 
worst  possible  conductors. 

It  certainly  appears  to  me  that  this  cause  is 
totally  inadequate  to  induce  a  powerful  current  of 
great  depth,  six  thousand  miles  long  and  several 
thousand  miles  in  width,  the  effect  which  Dr.  Car- 
penter attributes  to  it. 

During  the  summer  of  1870,  and  afterwards  in 
1871,  Dr.  Carpenter  made  a  series  of  observations  on 
the  current  in  the  Strait  of  Gibraltar.  The  existence 
of  an  under-current  out  of  the  Mediterranean  was 
considered  to  be  established  by  these  observations, 
and  the  conclusions  arrived  at  as  to  its  cause  did  not 
differ  materially  from  those  already  very  generally 


374  ^^^  DEPTHS  OF  THE  SEA.  [chap,  vui 

accepted.  Dr.  Carpenter  believes,  however,  that  the 
conditions  in  the  Strait  of  Gibraltar  and  in  the 
Baltic  Sound  aptly  illustrate  the  general  circulation 
in  the  ocean,  and  confirm  his  views. 

I  quote  from  the  general  summary  of  Dr.  Car- 
penter's address  to  the  Geographical  Society  : — 

"  The  application  of  the  foregoing  principles  to 
the  particular  cases  discussed  in  the  paper  is  as 
follows  : — 

''VIII. — A  vertical  circulation  is  maintained  in 
the  Strait  of  Gibraltar  by  the  excess  of  evaporation 
in  the  Mediterranean  over  the  amount  of  fresh  water 
returned  into  its  basin,  which  at  the  same  time 
lower's  its  level  and  increases  its  density;  so  that 
the  surface  inflow  of  salt  water  which  restores  its 
level  (exceeding  by  the  weight  of  salt  contained 
in  it  the  weight  of  fresh  water  which  has  passed  off 
by  evaporation)  disturbs  the  equilibrium  and  pro- 
duces a  deep  outflow^  which  in  its  turn  lowers  the 
level.  The  same  may  be  assumed  to  be  the  case 
in  the  Strait  of  Babelmandeb. 

''  IX. — A  vertical  circulation  is  maintained  in  the 
Baltic  Sound  by  an  excess  in  the  influx  of  fresh 
water  into  the  Baltic;  which  at  the  same  time 
raises  its  level  and  diminishes  its  density,  so  as  to 
produce  a  surface  outflow,  leaving  tlie  Baltic  column 
the  lighter  of  the  two,  so  that  a  deep  inflow  must 
take  place  to  restore  the  equilibrium.  The  same 
may  be  assumed  to  be  the  case  in  the  Bosphorus  and 
Dardanelles. 

'' X. —  A  vertical  circulation  must,  on  the  same 
principles,  be  maintained  between  polar  and  equa- 
torial waters  by  the  difference  of  their  temperatures  : 


CHAP.  VIII.]  THE  GULF-STREAM.  375 

the  level  of  the  pola^r  water  being  reduced,  and  its 
density  increased  by  the  surface-co/c?  to  which  it  is 
subjected,  whilst  a  downward  motion  is  also  imparted 
to  each  stratum  successively  exposed  to  it ;  and  the 
level  of  equatorial  water  being  raised  and  its  density 
diminished  by  the  surface-^^a^  to  which  it  is  exposed. 
(The  first  of  these  agencies  is  by  far  the  more  effec- 
tive, since  it  extends  to  the  whole  depth  of  the  water, 
whilst  the  second  only  affects,  in  any  considerable 
degree,  the  superficial  stratum.)  Thus  a  movement 
will  be  imparted  to  the  upper  stratum  of  oceanic 
water  from  the  equator  towards  the  poles,  whilst  a 
movement  will  be  imparted  to  the  deeper  stratum 
from  the  poles  towards  the  equator." 

It  seems  to  me  that  the  doctrine  here  propounded 
by  my  distinguished  colleague,  if  I  understand  it 
aright,  is  open  to  the  objection  to  which  I  have 
already  referred  in  connection  with  the  speculations 
of  Captain  Maury. 

If  the  currents  flow  in  the  direction  and  with  the 
permanence  accepted  by  Dr.  Carpenter  in  the  Strait 
of  Gibraltar  and  in  the  Baltic  Sound,  if  their  flow 
and  its  direction  be  due  to  the  causes  to  which  Dr. 
Carpenter  attributes  them,  and  if  there  be  any 
analogy  whatever  between  the  conditions  of  equi- 
librium of  these  inland  seas  and  that  of  the  outer 
ocean, — none  of  which  propositions  appear  to  me  at 
all  satisfactorily  proved, — I  should  think  that  the  vast 
equatorial  region,  the  path  of  the  trade-winds  and  the 
belt  of  vertical  solar  radiation,  must,  so  far  as  eva- 
poration is  concerned,  resemble,  or  rather  greatly 
exaggerate,  the  conditions  of  the  Mediterranean.  The 
consequent  accumulation  of  salt,^ — through  the  whole 


376  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

depth  of  course,  the  hrine  sinking  downwards, — must 
sjreatly  outweigh  (I  give  this  as  what  Petermann 
would  call  a  gratuitous  speculation)  the  slight  ex- 
pansion caused  by  the  heating  of  the  surface  layer. 
The  more  restricted  arctic  basin  on  the  other  hand, 
as  was  long  ago  pointed  out  by  Capt.  Maury,  partici- 
pates to  a  certain  extent  in  the  characteristics  of 
the  Baltic;  and  I  am  greatly  mistaken  if  the  low 
specific  gravity  of  the  polar  sea,  the  result  of  the 
condensation  and  precipitation  of  vapour  evaporated 
from  the  intertropical  area,  do  not  fully  counter- 
balance the  contraction  of  the  superficial  film  by 
arctic  cold. 

The  North  Atlantic  ocean  bears  a  proportion 
in  depth  to  the  mass  of  the  earth  considerably 
less  than  that  of  the  paper  covering  an  eighteen- 
inch  globe  to  that  of  the  globe  it  covers,  while 
the  film  heated  by  direct  solar  radiation  may  be 
represented  by  its  surface  coating  of  varnish, 
and  is  not  actually  thicker  than  the  height  of 
St.  Paul's.  Physicists  seem  to  find  a  difficulty  in 
giving  us  the  amount  of  palpable  efPect  in  pro- 
ducing currents  in  this  shell  of  water,  six  thousand 
miles  in  length  by  three  thousand  in  width  and 
two  miles  in  thickness,  which  may  be  due  to  causes 
such  as  those  relied  upon  by  Dr.  Carpenter,  acting 
under  the  peculiar  circumstances  and  to  the  amount 
in  which  we  find  them  in  nature;  and  probably  we 
are  not  yet  in  a  position  to  give  them  sufficient  data 
to  enable  them  to  do  so.  Mr.  Croll,  a  good  authority 
in  such  matters,  has  attempted  to  make  some  calcu- 
tions,  and  comes  to  the  conclusion  that  none  of  them 
are  sufficient  to  overcome  the  friction  of  water  and  to 


CHAP,  viii.]  THE  GULF-STREAM.  377 

produce  any  current  whatever ;  ^  but  in  tliis  view  he 
does  not  certainly  receive  universal  support.  I  am 
myself  inclined  to  believe  that  in  a  great  body  of 
salt  water  at  different  temperatures,  with  unequal 
amounts  of  evaporation,  under  varying  barometric 
pressures,  and  subject  to  the  drift  of  variable  winds, 
currents  of  all  kinds,  great  and  small,  variable  and 
more  or  less  permanent,  must  be  set  up ;  ^  but  the 
probable  result  appears  to  be  reduced  to  a  minimum 
when  we  find  that  causes,  themselves  of  doubtful 
efficiency,  actually  antagonize  one  another ;  and  that 
we  are  obliged  to  trust  for  the  final  effect  to  the 
amount  by  which  the  least  feeble  of  these  exceeds 
the  others  in  strength.  Speaking  in  the  total  ab- 
sence of  all  reliable  data,  it  is  my  general  impres- 
sion that,  if  we  were  to  set  aside  all  other  agencies, 
and  to  trust  for  an  oceanic  circulation  to  those  con- 
ditions only  which  are  relied  upon  by  Dr.  Carpenter, 
if  there  were  any  general  circulation  at  all,  which 
seems  very  problematical,  the  odds  are  rather  in 
favour  of  a  warm  under-current  travelling  north- 
wards by  virtue  of  its  excess  of  salt,  balanced  by  a 
surface  return-current  of  fresher  though  colder  arctic 
water. 

With  regard,  then,  to  this  question  of  a  general 
circulation  caused  by  difference  in  specific  gravity, 
for  the  present  I  cordially  endorse  the  opinion  ex- 
pressed by  the  late  Sir  John  Herschel  in  a  cautious 

^  James  CroU,  op.  cit. 

2  On  the  Distribution  of  Temperatures  in  the  North  Atlantic. 
An  Address  delivered  to  the  Meteorological  Society  of  Scotland  at 
the  General  Meeting  of  the  Society  July  5th,  1871,  by  Professor 
Wyville  Thomson. 


378  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

and  excellent  letter  addressed  to  Dr.  Carpenter — a 
letter  which  there  is  no  impropriety  in  my  quoting  in 
full  as  it  is  already  in  print,  and  which  has  a  special 
interest  as  being  probably  one  of  the  last  written 
by  Sir  John  Herschel  on  scientific  subjects : — 


•*  CoLLiNGWooD,  April  9th,  1871. 

"My  dear  Sir, — Many  thanks  for  your  paper  on  the  Gib- 
raltar current  and  the  Gulf-stream.  Assuredly,  after  well  con- 
sidering all  you  say,  as  well  as  the  common  sense  of  the  matter, 
and  the  experience  of  our  hot-water  circulation  pipes  in  our 
greenhouses,  &c.,  there  is  no  refusing  to  admit  that  an  oceanic 
circulation  of  some  sort  must  arise  from  mere  heat,  cold,  and 
evaporation,  as  verce  causae,  and  you  have  brought  forward  with 
singular  emphasis  the  more  powerful  action  of  the  polar  cold,  or 
rather  the  more  intense  action,  as  its  maximum  effect  is  limited 
to  a  much  smaller  area  than  that  of  the  maximum  of  equatorial 
heat. 

"The  action  of  the  trade  and  counter-trade  winds,  in  like 
manner,  cannot  be  ignored ;  and  henceforward  the  question  of 
ocean  currents  will  have  to  be  studied  under  a  twofold  point  of 
view.  The  wind-currents,  however,  are  of  easier  investigation  : 
all  the  causes  lie  on  the  surface ;  none  of  the  agencies  escape 
our  notice ;  the  configuration  of  coasts,  which  mainly  determines 
their  direction,  is  patent  to  sight.  It  is  otherwise  with  the  other 
class  of  movements.  They  take  place  in  the  depths  of  the  ocean ; 
and  their  movements  and  directions  and  channels  of  concentra- 
tion are  limited  to  the  configuration  of  the  sea-bottom,  which 
has  to  be  studied  over  its  entire  surface  by  the  very  imperfect 
method  of  sounding. 

"  I  am  glad  you  succeeded  in  getting  specimens  of  Mediter- 
ranean water  near  the  place  of  the  presumed  salt  spring  of 
Smyth  and  Wollaston,  making  it  clear  that  the  whole  affair 
must  have  arisen  from  some  accidental  substitution  of  one 
bottle  for  another,  or  from  evaporation.  I  never  put  any  hearty 
faith  in  it. 


CHAP.  VIII.]  THE  GULF-STREAM.  379 

"  So,  after  all,  there  is  an  under-current  setting  outwards  in 
the  Straits  of  Gibraltar. 

"Eepeating  my  thanks  for  this  interesting  memoir,  believe 
me,  dear  Sir, 

"  Yours  very  truly, 

"J.  E.  W.  Herschel. 

*'Dr.  W.  B.  Carpenter.'''^ 

The  second  view,  supported  by  Dr.  Petermann  of 
Gotlia,  and  by  most  of  the  leading  authorities  in 
physical  geography  in  Germany  and  Northern 
Europe,  and  strongly  urged  by  the  late  Sir  John 
Herschel  in  his  'Outlines  of  Physical  Geography' 
published  in  the  year  1846,  attributes  nearly  the 
whole  of  the  sensible  phenomena  of  heat-distribution 
in  the  North  Atlantic  to  the  Gulf- stream,  and  to  the 
arctic  return-currents  which  are  induced  by  the 
removal  of  tropical  water  towards  the  polar  regions 
by  the  Gulf-stream.  If  we  for  a  moment  admit  that 
to  the  Gulf-stream  is  due  almost  exclusively  the 
singular  advantage  in  climate  which  the  eastern 
borders  of  the  North  Atlantic  possess  over  the 
western,  the  origin  of  this  great  current,  its  extent 
and  direction,  and  the  nature  and  amount  of  its 
influence,  become  questions  of  surpassing  interest. 
Before  considering  these,  however,  it  will  be  well 
to  define  what  is  here  meant  by  the  term  *  Gulf- 
stream,'  for  even  on  this  point  there  has  been  a  good 
deal  of  misconception. 

I  mean  by  the  Gulf-stream  that  mass  of  heated 
water  which  pours  from  the  Strait  of  Florida  across 
the  North  Atlantic,  and  likewise  a  wider  but  less 
definite  warm  current,  evidently  forming  part  of  the 
same  great  movement  of  water,  which  curves  north- 

^  Nature,  vol.  iv.  p.  7L 


380  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

wards  to  the  eastward  of  the  AYest  Indian  Islands. 
I  am  myself  inclined,  without  hesitation,  to  regard 
this  stream  as  simply  the  reflux  of  the  equatorial 
current,  added  to  no  doubt  during  its  north-easterly 
course,  by  the  surface-drift  of  the  anti-trades  which 
follows  in  the  main  the  same  direction. 

The  scope  and  limit  of  the  Gulf- stream  will  be 
better  understood  if  we  inquire  in  the  first  place  into 
its  origin  and  cause.  As  is  well  known, — in  two 
bands,  one  to  the  north  and  the  other  to  the  south 
of  the  equator, — the  north-east  and  south-east  trade- 
winds,  reduced  to  meridional  directions  by  the  east- 
ward frictional  impulse  of  the  earth's  rotation,  drive 
before  them  a  magnificent  surface  current  of  hot 
water  4,000  miles  long  by  450  miles  broad  at  an 
average  rate  of  thirty  miles  a  day.  Off  the  coast  of 
Africa  near  its  starting-point  to  the  south  of  the 
Islands  of  St.  Thomas  and  Anna  Bon,  this  'Equa- 
torial Current '  has  a  speed  of  forty  miles  in  the 
twenty-four  hours,  and  a  temperature  of  23°  C. 

Increasing  quickly  in  bulk,  and  spreading  out 
more  and  more  on  both  sides  of  the  equator,  it  flows 
rapidly  due  west  towards  the  coast  of  South  America. 
At  the  eastern  point  of  South  America,  Cape  St. 
Roque,  the  equatorial  current  splits  into  two,  and 
one  portion  trends  southwards  to  deflect  the  isotherms 
of  21°,  15°-5, 10°,  and  4°-5  C.  into  loops  upon  our  maps, 
thus  carrying  a  scrap  of  comfort  to  the  ^Falkland 
Islands  and  Cape  Hoorn ;  while  the  northern  portion 
follows  the  north-east  coast  of  South  America,  gaining 
continually  in  temperature  under  the  influence  of  the 
tropical  sun.  Its  speed  has  now  increased  to  sixty- 
eight  miles  in  twenty -four  hours,  and  by  the  union 


CHAP,  viii]  THE  GULF-STREAM.  381 

with  it  of  the  waters  of  the  river  Amazon,  it  rises  to 
one  hundred  miles  (6 '5  feet  in  a  second),  but  it  soon 
falls  off  again  when  it  gets  into  the  Caribbean  sea. 
Plowing  slowly  through  the  w^hole  length  of  this  sea, 
it  reaches  the  Gulf  of  Mexico  through  the  Strait  of 
Yucatan,  when  a  part  of  it  sweeps  immediately  round 
Cuba ;  but  the  main  stream  "having  made  the  circuit 
of  the  Gulf  of  Mexico,  passes  through  the  Strait  of 
[Florida ;  thence  it  issues  as  the  '  Gulf-stream  '  in  a 
majestic  current  upwards  of  thirty  miles  broad,  two 
thousand  two  hundred  feet  deep,  with  an  average 
velocity  of  four  miles  an  hour,  and  a  temperature  of 
86°  Eahr.  (30°  C)/'  ^  The  hot  water  pours  from  the 
strait  with  a  decided  though  slight  north-easterly 
impulse  on  account  of  its  great  initial  velocity.  Mr. 
Croll  calculates  the  Gulf-stream  as  equal  to  a  stream 
of  water  fifty  miles  broad  and  a  thousand  feet  deep 
flowing  at  a  rate  of  four  miles  an  hour ;  consequently 
conveying  5,575,680,000,000  cubic  feet  of  water  per 
hour,  or  133,816,320,000,000  cubic  feet  per  day.  This 
mass  of  water  has  a  mean  temperature  of  18°  C.  as  it 
passes  out  of  the  gulf,  and  on  its  northern  journey  it 
is  cooled  down  to  4°*5,  thus  losing  heat  to  the  amount 
of  13°* 5  C.  The  total  quantity  of  heat  therefore  trans- 
ferred from  the  equatorial  regions  per  day  amounts 
to  something  like  154,959,300,000,000,000,000  foot- 
pounds.^ 

This  is   nearly   equal   to   the  whole   of  the   heat 

^  Physical  Geography.  From  the  'Encyclopaedia  Britannica.'  By 
Sir  John  F.  W.  Herschel,  Bart.,  K.H.P.     Edinburgh,  1861,  p.  49. 

2  On  Ocean  Currents.  By  James  Croll,  of  the  Geological  Survey  of 
Scotland.  Part  I.  Ocean  Currents  in  relation  to  the  Distribution  of 
Heat  over  the  Globe     (Philosophical  Magazine.     February  1870.) 


382  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

received  from  the  sun  by  the  Arctic  regions,  and, 
reduced  by  a  half  to  avoid  all  possibility  of  exaggera- 
tion, it  is  still  equal  to  one-fifth  of  the  whole  amount 
received  from  the  sun  by  the  entire  area  of  the  N  orth 
Atlantic.  The  Gulf- stream,  as  it  issues  from  the  Strait 
of  Florida  and  expands  into  the  ocean  on  its  north- 
ward course,  is  probably  the  most  glorious  natural 
phenomenon  on  the  face  of  the  earth.  The  water  is 
of  a  clear  crystalline  transparency  and  an  intense 
blue,  and  long  after  it  has  passed  into  the  open  sea  it 
keeps  itself  apart,  easily  distinguished  by  its  warmth, 
its  colour,  and  its  clearness ;  and  with  its  edges  so 
sharply  defined  that  a  ship  may  have  her  stem  in 
the  clear  blue  stream  while  her  stern  is  still  in  the 
common  water  of  the  ocean. 

"  The  dynamics  of  the  Gulf-stream  have  of  late, 
in  the  work  of  Lieutenant  Maury  already  mentioned, 
been  made  the  subject  of  much  (we  cannot  but  think 
misplaced)  wonder,  as  if  there  could  be  any  possible 
ground  for  doubting  that  it  owes  its  origin  entirely 
to  the  trade-winds."  ^  Setting  aside  the  wider  ques- 
tion of  the  possibility  of  a  general  oceanic  circulation 
arising  from  heat,  cold,  and  evaporation,  I  believe 
that  Captain  Maury  and  Dr.  Carpenter  are  the  only 
authorities  who  of  late  years  have  disputed  this 
source  of  the  current  which  we  see,  and  can  gauge 
and  measure  as  it  passes  out  of  the  Strait  of  Florida ; 
for  it  is  scarcely  necessary  to  refer  to  the  earlier 
speculations  that  it  is  caused  by  the  Mississippi  river, 
or  that  it  flows  downwards  by  gravitation  from  a 
'  head '  of  water  produced  by  the  trade- winds  in  the 
Caribbean  sea. 

^  Herscliel,  op.  cit.  p.  51. 


I 


CHAP.  VIII.]  THE  GULF-STREAM.  383 

Captain  Maury  writes^  that  "the  dynamical  force 
that  calls  forth  the  Gulf-stream  is  to  be  found  in  the 
difference  as  to  specific  gravity  of  intertropical  and 
polar  waters."  ''  The  dynamical  forces  which  are 
expressed  by  the  Gulf-stream  may  with  as  much  pro- 
priety be  said  to  reside  in  those  northern  waters  as 
in  the  West  India  seas  :  for  on  one  side  we  have  the 
Caribbean  sea  and  Gulf  of  Mexico  with  their  waters 
of  brine ;  on  the  other  the  great  polar  basin,  the 
Baltic,  and  the  North  Sea,  the  two  latter  with  waters 
which  are  little  more  than  brackish.  In  one  set  of 
these  sea-basins  the  water  is  heavy;  in  the  other  it  is 
light.  Between  them  the  ocean  intervenes ;  but  water 
is  bound  to  seek  and  to  maintain  its  level ;  and  here, 
therefore,  we  unmask  one  of  those  agents  concerned 
in  causing  the  Gulf-stream.  What  is  the  power  of  this 
agent  ?  Is  it  greater  than  that  of  other  agents  ?  and 
how  much  ?  We  cannot  say  how  much ;  we  only 
know  it  is  one  of  the  chief  agents  concerned.  More- 
over, speculate  as  we  may  as  to  all  the  agencies  con- 
cerned in  collecting  these  waters,  that  have  supplied 
the  trade-winds  with  vapour,  into  the  Caribbean  Sea, 
and  then  in  driving  them  across  the  Atlantic,  we  are 
forced  to  conclude  that  the  salt  which  the  trade-wind 
vapour  leaves  behind  it  in  the  tropics  has  to  be  con- 
veyed away  from  the  trade- wind  region,  to  be  mixed 
up  again  in  due  proportion  with  the  other  water  of 
the  sea — the  Baltic  Sea  and  the  Arctic  Ocean  included 
— and  that  these  are  some  of  the  waters,  at  least, 
which  we  see  running  off  through  the  Gulf- stream. 
To  convey  them  away  is  doubtless  one  of  the  offices 
which  in  the  economy  of  the  ocean  has  been  assigned 

1  Maury's  Physical  Geography  of  the  Sea,  op.  cit. 


384  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

to  it.  But  as  for  the  seat  of  the  forces  which  put 
and  keep  the  Gulf-stream  in  motion,  theorists  may 
place  them  exclusively  on  one  side  of  the  ocean  with 
as  much  philosophical  propriety  as  on  the  other. 
Its  waters  find  their  way  into  the  North  Sea  and 
Arctic  Ocean  by  virtue  of  their  specific  gravity,  while 
water  thence,  to  take  their  place,  is,  by  virtue  of  its 
specific  gravity  and  by  counter- currents,  carried  back 
into  the  gulf.  The  dynamical  force  which  causes  the 
Gulf-stream  may  therefore  be  said  to  reside  both  in 
the  polar  and  in  the  intertropical  waters  of  the 
Atlantic." 

According  to  this  view,  the  tropical  water  finds  its 
way  on  account  of  its  greater  weight  towards  the  poles, 
while  the  polar  water,  owing  to  its  less  weight,  moves 
southwards  to  replace  it.  The  general  result  would 
be  of  course  a  system  of  warm  under-  and  cold 
surface-currents,  and  these  we  do  not  find.  I  merely 
quote  the  passage  as  a  curious  illustration  of  the 
adage  that  on  most  questions  a  good  deal  can  be 
said  on  both  sides. 

We  have  already  considered  the  doctrine  of  a  general 
oceanic  circulation,  which  has  been  so  strongly  ad- 
vocated of  late  by  Dr.  Carpenter,  and  I  have  merely 
to  advert  in  this  place  to  th,e  bearing  which  that 
doctrine  has  upon  our  views  as  to  the  origin  of  the 
Gulf-stream ;  its  bearings  on  the  extension  and  dis- 
tribution of  the  current  will  be  discussed  hereafter. 
As  already  stated.  Dr.  Carpenter  attributes  all  the 
great  movements  of  ocean  water  to  a  general  con- 
vective  circulation,  and  of  this  general  circulation 
he  regards  the  Gulf- stream  as  a  peculiarly  modi- 
fied case.     In  the  passage  already  quoted  (p.  370)  of 


CHAP.  VIII.]  THE  GULF-STREJM.  385 

his  address  to  the  Eoyal  Institution,  Dr.  Carpenter 
states,  that  "  the  Gulf-stream  constitutes  a  peculiar 
case,  modified  by  local  conditions,"  of  "a  great 
general  movement  of  equatorial  water  towards  the 
polar  area."  I  confess  I  feel  myself  compelled  to 
take  a  totally  different  view.  It  seems  to  me  that 
the  Gulf-stream  is  the  one  natural  physical  pheno- 
menon on  the  surface  of  the  earth  whose  origin  and 
principal  cause,  the  drift  of  the  trade-winds,  can  be 
most  clearly  and  easily  traced. 

The  further  progress  and  extension  of  the  Gulf- 
stream  through  the  North  Atlantic  in  relation  to 
influence  upon  climate  has  been,  however,  a  fruitful 
source  of  controversy.  The  first  part  of  its  course, 
after  leaving  the  strait,  is  sufficiently  evident,  for 
its  water  long  remains  conspicuously  different  in 
colour  and  temperature  from  that  of  the  ocean, 
and  a  current  having  a  marked  effect  on  naviga- 
tion is  long  perceptible  in  the  peculiar  Gulf-stream 
water.  *'  Narrow  at  first,  it  flows  round  the  penin- 
sula of  Florida,  and,  with  a  speed  of  about  70  or 
80  miles,  follows  the  coast  at  first  in  a  due  north, 
afterwards  in  a  north-east  direction.  At  the  lati- 
tude of  Washington  it  leaves  the  North  American 
coast  altogether,  keeping  its  north-eastward  course ; 
and  to  the  south  of  the  St.  George's  and  New- 
foundland Banks  it  spreads  its  waters  more  and 
more  over  the  Atlantic  Ocean,  as  far  as  the  -A9ores. 
At  these  islands  a  part  of  it  turns  southwards  again 
towards  the  African  coast.  The  Gulf-stream  has, 
so  long  as  its  waters  are  kept  together  along  the 
American  coast,  a  temperature  of  26°-6  C. ;  but, 
even   under  north   latitude  36°,  Sabine  found    that 

c  c 


386  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

23°*3  C.  at  the  beginning  of  December,  while  the 
sea- water  beyond  the  stream  showed  only  16°* 9  C. 
Under  north  latitude  40 — 41''  the  water  is,  accord- 
ing to  Humboldt,  at  22^-5  C.  within,  and  17°-5  C. 
without  the  stream."^ 

The  Gulf-stream  off  the  coast  of  North  America 
has  been  most  carefully  examined  by  the  officers  of 
the  United  States  Coast  Survey,  at  first  under  the 
superintendence  of  Professor  Bache,  and  latterly 
under  the  direction  of  the  present  able  head  of  the 
bureau,  Professor  Pierce.  In  1860  Professor  Bache 
published  an  account  of  the  general  result.  ^  Pour- 
teen  sections  through  the  Gulf-stream  had  been  care- 
fully surveyed  at  intervals  of  about  100  miles  along 
the  coast — the  first  almost  within  the  Gulf  of  Mexico, 
from  Portingas  to  Havana,  and  the  last  off  Cape 
Cod,  lat.  41°  N.,  where  the  stream  loses  all  parallel- 
ism with  the  American  coast  and  trends  to  the  east- 
ward. These  sections  fully  illustrate  the  leading 
phenomena  during  this  earlier  part  of  its  course 
of  this  wonderful  current,  which  Professor  Bache 
well  characterizes  as  "  the  great  hydrographic  feature 
of  the  United  States." 

Opposite  Portingas,  passing  along  the  Cuban  coast, 
the  stream  is  unbroken  and  the  current  feeble ;  the 
temperature  at  the  surface  is  about  26"'* 7  C.  Issuing 
from  the  Strait  of  Bernini  the  current  is  turned 
nearly  directly  northwards  by  the  form  of  the  land ; 

1  Professor  Buff,  op.  cit.  p.  199. 

2  Lecture  on  the  Gulf-stream,  prepared  at  the  request  of  the 
American  Association  for  the  Advancement  of  Science,  by  A.  D.  Bache, 
Superintendent  U.S.  Coast  Survey.  'Fmm  the  A merwan  Journal  of 
Science  and  Arts,  vol.  xxx.  I^ovember  1860.  5 

I 


CHAP.  VIII.]  THE  GULF-STREAM.  387 

a  little  to  the  north  of  the  strait,  the  rate  is  from 
three  to  five  miles  an  hour.  The  depth  is  only  325 
fathoms,  and  the  bottom,  which  in  the  Strait  of 
Florida  was  a  simple  slope  and  counter- slope,  is 
now  corrugated.  The  surface  temperature  is  about 
26°-5  C,  while  the  bottom  temperature  is  4°-5 ;  so 
that  in  the  moderate  depth  of  325  fathoms  the  equa- 
torial current  above  and  the  polar  counter-current 
beneath  have  room  to  pass  one  another,  the  current 
from  the  north  being  evidently  tempered  consider- 
ably by  mixture.  North  of  Mosquito  inlet  the 
stream  trends  to  the  eastward  of  north,  and  off  St. 
Augustine  it  has  a  decided  set  to  the  eastward 
Between  St.  Augustine  and  Cape  Hatteras  the  set 
of  the  stream  and  the  trend  of  the  coast  differ  but 
little,  making  5°  of  easting  in  5°  of  northing.  At 
Hatteras  it  curves  to  the  northward,  and  then  runs 
easterly.  In  the  latitude  of  Gape  Charles  it  turns 
quite  to  the  eastward,  having  a  velocity  of  from  a 
mile  to  a  mile  and  a  half  in  the  hour. 

A  brief  account  of  one  of  the  sections  will  best 
explain  the  general  phenomena  of  the  stream  off  the 
coast  of  America.  I  will  take  the  section  following 
a  line  at  right  angles  to  the  coast  off  Sandy  Hook. 
.From  the  shore   out,  for  a  distance  of  about   250 

dies,  the  surface  temperature  gradually  rises  from 
21°  to  24°  C;  at  10  fathoms  it  rises  from  19°  to  22°  C. ; 
and  at  20  fathoms  it  maintains,  with  a  few  irregu- 
larities, a  temperature  of  19°  C.  throughout  the  whole 
space;  while  at  100,  200,  300,  and  400  fathoms  it 
maintains  in  like  manner  the  respective  temperatures 
of  8°-8,  5°-7,  4°-5,  and  2°-5  C.  This  space  is  therefore 
occupied  by  cold  water,  and  observation   has   suffi- 

c  c  2 


388  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

ciently  proved  that  the  low  temperature  is    due  to 
a  branch   of  the   Labrador   current   creeping   down 
along    the    coast   in   a   direction    opposite    to    that 
of  the  Gulf-stream.      In  the  Strait  of  Florida  this 
cold  stream  divides — one  portion  of  it  passing  under 
the  hot  Gulf-stream  water  into  the  Gulf  of  Mexico, 
while  the  remainder  courses  round  the  western  end 
of  Cuba.     240  miles  from  the  shore  the  whole  mass 
of  water  takes  a  sudden  rise  of  about  10°  C.  within 
25  miles,  a  rise  affecting  nearly  equally  the  water  at 
all  depths,  and  thus  producing  the  singular  pheno- 
menon  of    two   masses    of    water   in   contact — one 
passing    slowly    southwards,    and    the    other    more 
rapidly  northwards,  at  widely  different  temperatures 
at  the  same  levels.     This  abutting  of  the  side  of  the 
cold  current  against  that  of  the  Gulf-stream  is  so 
abrupt  that  it   has  been  aptly  called  by  Lieutenant 
George  M.  Bache  the  '  Cold  wall.'     Passing  the  cold 
wall  we  reach   the  Gulf- stream,   presenting    all    its 
special  characters  of  colour  and  transparency  and  of 
temperature.     In  the  section  which  we  have  chosen 
as  an  example,  upwards  of  three  hundred  miles  in 
length,  the   surface  temperature   is   about  26°  5  C, 
but  the  heat  is  not  uniform  across  the  stream,  for 
we   find   that   throughout  its   entire   length,  as  far 
south  as  the  Cape  Canaveral  section,  the  stream  is 
broken    up   into   longitudinal   alternating   bands   of 
warmer  and  cooler  water.     Off  Sandy  Hook,  beyond 
the   cold  wall,  the    stream  rises  to  a  maximum  of 
27°*8  C,   and  this  warm  band  extends  for  about  60 
miles.     The  temperature  then  falls  to  a  minimum  of 
26°* 5  C,  which  it  retains  for  about  30   miles,  when 
a  second  maximum  of  27°*4  succeeds,  which  includes 


CHAP.  VIII.]  THE  GULF-STREAM.  339 

the  axis  of  the  Gulf-stream,  and  is  about  170  miles 
wide.  This  is  followed  hj  a  second  minimum  of 
25°'5  C,  and  this  by  a  third  maximum,  when  the 
bands  become  indistinct.  It  is  singular  that  the 
minimum  bands  correspond  with  valley-like  depres- 
sions in  the  bottom,  w^hich  follow  in  succession  the 
outline  of  the  coast  and  lodge  de^p  southward  exten- 
sions of  the  polar  indraught. 

The  last  section  of  the  Gulf-stream  surv^eyed  by 
the  American  Hydrographers  extends  in  a  south- 
easterly direction  from  Cape  Cod,  lat.  41°  N.,  and 
traces  the  Gulf-stream,  still  broken  up  by  its  bands 
of  unequal  temperature,  spreading  directly  eastward 
across  the  Atlantic;  its  velocity  has,  however,  now 
become  inconsiderable,  and  its  limits  are  best  traced 
by  the  thermometer. 

The  course  of  the  Gulf-stream  beyond  this  point 
has  given  rise  to  much  discussion.  I  again  quote 
Professor  Buff  for  what  may  be  regarded  as  the 
view  most  generally  received  among  Physical  Geo- 
graphers : — 

"A  great  part  of  the  warm  water  is  carried  partly 
by  its  own  motion,  but  chiefly  by  the  prevailing  west 
and  north-west  winds,  towards  the  coasts  of  Europe 
and  even  beyond  Spitzbergen  and  Nova  Zembla ;  and 
thus  a  part  of  the  heat  of  the  south  reaches  far  into 
the  Arctic  Ocean.  Hence,  on  the  north  coast  of  the 
old  Continent,  we  always  find  driftwood  from  the 
southern  regions,  and  on  this  side  the  Arctic  Ocean 
remains  free  from  ice  during  a  great  part  of  the  year, 
even  as  far  up  as  80°  north  latitude;  while  on  the 
opposite  coast  (of  Greenland)  the  ice  is  not  quite 
thawed  even  in  summer."     The  two  forces  invoked 


390  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

by  Professor  Buff  to  perform  the  work  are  thus  the 
vis  a  tergo  of  the  trade-wind  drift,  and  the  direct 
driving  power  of  the  anti-trades,  producing  what 
has  been  called  the  anti-trade  drift.  This  is  quite 
^n  accordance  with  the  views  here  advocated.  The 
proportion  in  which  these  two  forces  act,  it  is  un- 
doubtedly impossible  in  the  present  state  of  our 
knowledge  to  determine. 

Mr.  A.  G.  Eindlay,  a  high  authority  on  all  hydro- 
graphic  matters,  read  a  paper  on  the  Gulf-stream 
before  the  Royal  Geographical  Society,  reported  in 
the  13th  volume  of  the  Proceedings  of  the' Society. 
Mr.  Pindlay,  while  admitting  that  the  temperature 
of  north-eastern  Europe  is  abnormally  ameliorated  by 
a  surface-current  of  the  warm  water  of  the  Atlantic 
which  reaches  it,  contends  that  the  Gulf-stream  proper, 
that  is  to  say  the  water  injected,  as  it  were,  into 
the  Atlantic  through  the  Strait  of  Plorida  by  the 
impulse  of  the  trade-winds,  becomes  entirely  thinned 
out,  dissipated,  and  lost,  opposite  the  Newfoundland 
banks  about  lat.  45°  N.  The  warm  water  of  the 
southern  portion  of  the  North  Atlantic  basin  is  still 
carried  northwards ;  but  Mr.  Pindlay  attributes  this 
movement  solely  to  the  anti-trades — the  south-west 
winds — which  by  their  prevalence  keep  up  a  balance 
of  progress  in  a  north-easterly  direction  in  the  surface 
layer  of  the  water. 

Dr.  Carpenter  entertains  a  very  strong  opinion  that 
the  dispersion  of  the  Gulf-stream  may  be  affirmed  to 
be  complete  in  about  lat.  45°  N.  and  long.  35°  W. 
Dr.  Carpenter  admits  the  accuracy  of  the  projection 
of  the  isotherms  on  the  maps  of  Berghaus,  Dove 
Petermann,  and  Keith  Johnston,  and  he  admits  like- 


CHAP,  vm.]  THE  GULF-STREAM.  391 

wise  the  conclusion  that  the  abnormal  mildness  of  the 
climate  on  the  north-western  coast  of  Europe  is  due 
to  a  movement  of  equatorial  water  in  a  north-easterly- 
direction.  "What  I  question  is  the  correctness  of 
the  doctrine  that  the  north-east  flow  is  an  extension 
or  prolongation  of  the  Gulf-stream,  still  driven  on 
by  the  vis  a  tergo  of  the  trade-winds — a  doctrine 
which  (greatly  to  my  surprise)  has  been  adopted  and 
defended  by  my  colleague  Professor  Wyville  Thom- 
son. But  while  these  authorities  attribute  the  whole 
or  nearly  the  whole  of  this  flow  to  the  true  Gulf- 
stream,  I  regard  a  large  part,  if  not  the  whole,  of 
that  which  takes  place  along  our  own  western  coast, 
and  passes  north  and  north-east  between  Iceland  and 
Norway  towards  Spitzbergen,  as  quite  independent 
of  that  agency;  so  that  it  would  continue  if  the 
North  and  South  American  continents  were  so  com- 
pletely disunited  that  the  equatorial  currents  would 
be  driven  straight  onwards  by  the  trade-winds  into 
the  Pacific  Ocean,  instead  of  being  embayed  in  the 
Gulf  of  Mexico  and  driven  out  in  a  north-east  direc- 
tion through  the  'narrows'  off  Cape  Plorida."^  Dr. 
Carpenter  does  not  mean  by  this  to  endorse  Mr. 
Pindlay's  opinion  that  the  movement  beyond  the 
45th  parallel  of  latitude  is  due  solely  to  the  drift  of 
the  anti-trades ;  he  says,  ''  On  the  view  I  advocate, 
the  north-easterly  flow  is  regarded  as  due  to  the 
vis  a  f route  originating  in  the  action  of  cold  upon 
the  water  of  the  polar  area,  whereby  its  level  is 
always  tending  to  depression."  ^  The  amelioration 
of   the   climate   of   north-western    Europe    is    thus 

^  Dr.  Carpenter  :  Proceedings  of  the  Eoyal  Geographical  Society  for 
1870,  op.  cit.  2  Op.  cit. 


392  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

caused  by  a  '  modified  case '  of  the  general  oceanic 
circulation,  and  neither  by  the  Gulf-stream  nor  by 
the  anti-trade  drift. 

Although  there  are,  up  to  the  present  time,  very 
few  trustworthy  observations  of  deep-sea  tempera- 
tures, the  surface  temperature  of  the  North  Atlantic 
has  been  investigated  with  considerable  care.  The 
general  character  of  the  isothermal  lines  with  their 
singular  loop-like  northern  deflections,  has  long 
been  familiar  through  the  temperature  charts  of  the 
geographers  already  quoted,  and  of  late  years  a  pro- 
digious amount  of  data  have  been  accumulated  both 
abroad  and  by  our  own  Admiralty  and  Meteoro- 
logical Department. 

In  1870,  Dr.  Petermann,  of  Gotha,  published^  an 
extremely  valuable  series  of  temperature  charts, 
embodying  the  results  of  the  reduction  of  upwards 
of  100,000  observations,  derived  chiefly  from  the 
following  sources : — 

1.  Prom  the  wind  and  current  charts  of  Lieu- 
tenant Maury,  embodying  about  30,000  distinct 
temperature  observations. 

2.  Prom  50,000  observations  made  by  Dutch  sea- 
captains,  and  published  by  the  Government  of  the 
Netherlands. 

3.  Prom  the  journal  of  the  Cunard  steamers  be- 
tween Liverpool  and  New  York,  and  of  the  steamers 
of  the  Montreal  Company  between  Glasgow  and 
Belleisle. 

4.  Prom  the  data  collected  by  the  secretary  of  the 

^  Der  Golf-Strom  und  Standpunkt  der  thermometrischen  Kenntniss 
des  Nord-Atlantischen  Oceans  und  Landgebietes  im  Jahre  1870. 
Justus  Perthe's '  Geographische  Mittheilungen/  Band  16.    Gotha,  1 870. 


I 


CHAP.  VIII.]  THE  GULF-STREAM.  393 

Scottish  Meteorological  Society,  Mr.  Bachan,  with 
regard  to  the  temperature  of  the  sea  on  the  coasts 
of  Scotland. 

5.  From  the  publications  of  the  Norwegian  Insti- 
tute on  sea-temperatures  between  Norway,  Scotland, 
and  Iceland. 

6.  Prom  the  data  furnished  by  the  Danish  Rear- 
Ad  miral  Irminger  on  sea-temperature  between  Den- 
mark and  the  Danish  settlements  in  Greenland. 

7.  Prom  the  observations  made  by  Earl  Dufferin 
on  board  his  yacht  'Poam'  between  Scotland,  Ice- 
land,  Spitzbergen,  and  Norway. 

And  finally,  from  the  recent  observations  collected 
by  the  English,  Swedish,  German,  and  Russian  ex- 
peditions to  the  arctic  regions  and  towards  the 
North  Pole. 

Dr.  Petermann  has  devoted  the  special  attention 
of  a  great  part  of  his  life  to  the  distribution  of  heat 
on  the  surface  of  the  ocean,  and  the  accuracy  and  con- 
scientiousness of  his  work  in  every  detail  are  beyond 
the  shadow  of  a  doubt.  Plate  VII.  is  in  the  main 
copied  from  his  charts,  with  a  few  modifications  and 
additions  derived  from  additional  data.  The  remark- 
able diversion  of  the  isothermal  lines  from  their 
normal  course  is  undoubtedly  caused  by  surface  ocean- 
currents  conveying  warm  tropical  water  towards  the 
polar  regions.  This  is  no  matter  of  speculation,  for 
the  current  is  in  many  places  perceptible  through 
its  effect  on  navigation,  and  the  path  of  the  warm 
water  may  be  traced  by  dipping  the  thermometer 
into  it  and  noting  its  temperature. 

In  the  North  Atlantic  every  curve  of  equal  tem- 
perature, whether  for  the  summer,  for  the  winter,  for 


394  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

a  single  month,  or  for  the  whole  year,  instantly 
declares  itself  as  one  of  a  system  of  curves  which 
are  referred  to  the  Strait  of  Florida  as  a  source  of 
heat,  and  the  flow  of  warm  water  may  be  traced  in 
a  continuous  stream,  indicated  when  its  movement 
can  no  longer  be  observed  by  its  form, — fanning  out 
from  the  neighbourhood  of  the  Strait  across  the 
Atlantic,  skirting  the  coasts  of  Trance,  Britain,  and 
Scandinavia,  rounding  the  North  Cape  and  passing 
the  White  Sea  and  the  Sea  of  Kari,  bathing  the 
western  shores  of  Novaja  Semla  and  Spitzbergen, 
and  finally  coursing  round  the  coast  of  Siberia,  a 
trace  of  it  still  remaining  to  find  its  way  through 
the  narrow  and  shallow  Behring's  Strait  into  the 
North  Pacific  (see  Plate  YII.). 

Now,  it  seems  to  me  that  if  we  had  only  these 
curves  upon  the  chart,  deduced  from  an  almost  in- 
finite number  of  observations  which  are  themselves 
merely  laboriously  multiplied  corroborations  of  many 
previous  ones,  without  having  any  clue  to  their 
rationale,  we  should  be  compelled  to  admit  that 
whatever  might  be  the  amount  and  distribution  of 
heat  derived  from  a  general  oceanic  circulation, — 
whether  produced  by  the  prevailing  winds  of  the 
region,  by  convection,  by  unequal  barometric  pres- 
sure, by  tropical  heat,  or  by  arctic  cold, — the  Gulf- 
stream,  the  majestic  stream  of  warm  water  whose 
course  is  indicated  by  the  deflections  of  the  isother- 
mal lines,  is  sufficiently  powerful  to  mask  all  the 
rest,  and,  broadly  speaking,  to  produce  of  itself  all 
the  abnormal  thermal  phenomena. 

The  deep-sea  temperatures  taken  in  the  '  Porcu- 
pine' have  an  important  bearing  upon  this  question, 


CHAP.  viiT.]  THE  GULF-STREAM.  395 

since  they  give  us  the  depth  and  volume  of  the  mass 
of  water  which  is  heated  above  its  normal  tempera- 
ture, and  which  we  must  regard  as  the  softener  of 
the  winds  blowing  on  the  coasts  of  Europe.  Refer- 
ring to  Pig.  60,  in  the  Bay  of  Biscay,  after  passing 
through  a  shallow  band  superheated  by  direct  radia- 
tion, a  zone  of  warm  water  extends  to  the  depth  of 
800  fathoms,  succeeded  by  cold  water  to  a  depth  of 
nearly  two  miles.  In  the  Bockall  channel  (Fig.  59) 
the  w^arm  layer  has  nearly  the  same  thickness,  and 
the  cold  underlying  water  is  500  fathoms  deep.  Off* 
the  Butt  of  the  Lews  (i^ig.  56)  the  bottom  tem- 
perature is  5*''2  C.  at  767  fathoms,  so  that  there 
the  warm  layer  evidently  reaches  to  the  bottom. 
In  the  Eaeroe  channel  (Fig.  55)  the  warm  water 
forms  a  surface  layer,  and  the  cold  water  underlies 
it,  commencing  at  a  depth  of  200  fathoms, — 567 
fathoms  above  the  level  of  the  bottom  of  the  warm 
water  off  the  Butt  of  the  Lews.  The  cold  water 
abuts  against  the  warm^there  is  no  barrier  between 
them.  Part  of  the  warm  water  flows  over  the 
cold  indraught,  and  forms  the  upper  layer  in  the 
Pgeroe  channel  What  prevents  the  cold  water  from 
slipping,  by  virtue  of  its  greater  weight,  under  the 
warm  water  off  the  Butt  of  the  Lews  ?  It  is  quite 
evident  that  there  must  be  some  force  at  work 
keeping  the  warm  water  in  that  particular  position, 
or,  if  it  be  moving,  compelling  it  to  follow  that 
particular  course.  The  comparatively  high  tem- 
perature from  100  fathoms  to  900  fathoms  I  have 
always  attributed  to  the  northern  accumulation  of 
the  water  of  the  Gulf- stream.  The  amount  of  heat 
derived  directly  from   the   sun  by   the  water  as  it 


^ 


396  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

passes  through  any  particular  region,  must  be  re- 
garded, as  I  have  already  said,  as  depending  almost 
entirely  upon  latitude.  Taking  this  into  account, 
the  surface  temperatures  in  what  we  were  in  the 
habit  of  calling  the  '  warm  area '  coincided  precisely 
with  Petermann's  curves  indicating  the  northward 
path  of  the  Gulf-stream. 

I  extract  the  following  from  a  letter  dated  23rd 
September,  1872,  from  Professor  H.  Mohn,  director  of 
the  Norwegian  Meteorological  Institute  at  Christiania, 
to  Mr.  Buchan,  the  excellent  secretary  of  the  Scottish 
Meteorological  Society  : — "  I  have  this  summer  got 
some  deep-sea  temperatures  which  may  be  of  general 
interest  for  our  climate.  In  the  Throndhj ems-fjord 
I  found  16° '5  G.  on  the  surface,  and  from  50  fathoms 
to  the  bottom  (200  fathoms)  a  very  uniform  tempera- 
ture of  6°  5  C.  in  one  place,  and  6°  C.  in  another 
place  further  in.  In  the  Sceguefjord  I  found  16°  C. 
on  the  surface,  and  6°'5  C.  constantly  from  10  to 
700  fathoms.  Between  Iceland  and  Paeroe,  Lieu- 
tenant Mtiller,  commander  of  the  Bergen  and  Iceland 
steamer,  has  found  this  summer  8°  C.  at  the  bottom 
in  300  fathoms.  This  proves  that  the  Gulf-stream 
water  fills  the  whole  of  the  channel,  contrary  to 
what  is  the  case  in  the  Pgeroe-Shetland  channel, 
where  there  is  ice-cold  water  in  a  depth  of  300 
fathoms."  The  facts  here  mentioned  are  very 
important,  and  entirely  confirm  our  results ;  but  my 
chief  object  in  giving  the  quotation  is  to  show  the 
unhesitating  way  in  which  the  explanation  which 
attributes  the  high  temperature  of  the  sea  on  the 
Scandinavian  coast  to  the  Gulf-stream  is  adopted  by 
those  best  qualified  to  form  an  opinion. 


I 


I 


CHAP.  VIII.]  THE  G  ULF-STREAM.  397 

The  North  Atlantic  and  Arctic  seas  form  together 
a  cul  de  sac  closed  to  the  northward,  for  there  is 
practically  no  passage  for  a  hody  of  water  through 
Behring's  Strait.     While,  therefore,  a  large  portion 
of    the  water,  finding   no   free   outlet    towards   the 
north-east,  turns  southward  at  the  Azores,  the  re- 
mainder, instead  of  thinning  off,  has  rather  a  ten- 
dency to  accumulate   against   the   coasts   bounding 
the  northern  portions  of  the  trough.    "We  accordingly 
find  that  it  has  a  depth  off  the  west  coast  of  Iceland 
of  at   least   4,800   feet,   with    an    unknown  lateral 
extension.     Dr.  Carpenter,   discussing  this   opinion, 
says :    "  It  is  to  me   physically  inconceivable   that 
this  surface  film  of  lighter  (because  w^armer)  water 
should  collect  itself  together  again — even  supposing 
it   still   to   retain   any  excess   of  temperature — and 
should   burrow   downwards   into   tlie    '  trough,'   dis- 
placing colder  and  heavier  water,  to  a  depth  much 
greater  than  that  which  it  possesses  at  the  point  of 
its  greatest  'glory' — its  passage  through  the  Elorida 
Narrows.     The  upholders  of  this  hypothesis  have  to 
explain  how  such  a  re-collection  and  dipping-down 
of  the  Gulf-stream  water  is  to  be  accounted  for  on 
physical   principles."  ^      I   believe   that    as    a    rule, 
experimental  imitations  on  a  small  scale  are  of  little 
use  in  the  illustration  of  natural  phenomena ;  a  very 
simple  experiment  will,  however,  show  that  such  a 
process  is  possible.      If  we  put  a  tablespoonfal   of 
cochineal  into  a  can  of  hot  water,  so  as  to  give  it 
a  red  tint,  and  then  run  it  through  a  piece  of  india- 
rubber  tube  with  a  considerable  impulse  along  the 
surface  of  a  quantity  of  cold  water  in  a  bath,  we  see 

^  Dr.  Carpenter's  Address  to  Geographical  Society,  op.  cit. 


398  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

the  red  stream  widening  out  and  becoming  paler 
over  the  general  surface  of  the  water  till  it  reaches 
the  opposite  edge,  and  very  shortly  the  rapidly 
heightening  colour  of  a  band  along  the  opposite 
wall  indicates  an  accumulation  of  the  coloured  water 
where  its  current  is  arrested.  If  we  now  dip  the 
hand  into  the  water  of  the  centre  of  the  bath,  a  warm 
bracelet  merely  encircles  the  wrist ;  while  at  the  end 
of  the  bath  opposite  the  warm  influx,  the  hot  water, 
though  considerably  mixed,  envelopes  the  whole  hand. 

The  North  Atlantic  forms  a  basin  closed  to  the 
northward.  Into  the  corner  of  this  basin,  as  into  a 
bath, — with  a  north-easterly  direction  given  to  it  by 
its  initial  velocity,  as  if  the  supply  pipe  of  the  bath 
were  turned  so  as  to  give  the  hot  water  a  definite 
impulse, — this  enormous  flood  is  poured,  day  and 
night,  winter  and  summer.  When  the  basin  is  full 
— and  not  till  then — overcoming  its  northern  impulse, 
the  surplus  water  turns  southwards  in  a  southern 
eddy,  so  that  there  is  a  certain  tendency  for  the 
hot  water  to  accumulate  in  the  northern  basin, 
to  '  bank  down'  ^  along  the  north-eastern  coasts. 

It  is  scarcely  necessary  to  say  that  for  every  unit 
of  water  which  enters  the  basin  of  the  North 
Atlantic,  and  which  is  not  evaporated,  an  equivalent 
must  return.  As  cold  water  can  gravitate  into  the 
deeper  parts  of  the  ocean  from  all  directions,  it  is 
only  under  peculiar  circumstances  that  any  move- 
ment having  the  character  of  a  current  is  induced; 

*  Ocean  Currents.  An  Address  delivered  to  the  Eoyal  United 
Service  Institution  June  15th,  1871.  By  J.  K.  Laughton,  M.A., 
Kaval  Instructor  at  the  Eoyal  Naval  College.  (From  the  Journal  of 
the  Institution,  vol.  xv.) 


I 


OHAP.  vin.]  THE  GULF-STREAM.  399 

these  circumstances  occur,  however,  in  the  confined 
and  contracted  communication  between  the  North 
Atlantic  and  the  Arctic  Sea.  Between  Cape  Eare- 
well  and  North  Cape  there  are  only  two  channels 
of  any  considerable  depth,  the  one  very  narrow 
along  the  east  coast  of  Iceland,  and  the  other 
along  the  east  coast  of  Greenland.  The  shallow 
part  of  the  sea  is  entirely  occupied,  at  all  events 
during  summer,  by  the  warm  water  of  the  Gulf- 
stream,  except  at  one  point,  where  a  rapid  current 
of  cold  water,  very  restricted  and  very  shallow, 
sweeps  round  the  south  of  Spitzbergen  and  then 
dips  under  the  Gulf- stream  water  at  the  northern 
entrance  of  the  German  Ocean. 

This  cold  flow,  at  first  a  current,  finally  a  mere 
indraught,  affects  greatly  the  temperature  of  the 
German  Ocean ;  but  it  is  entirely  lost,  for  the  slight 
current  which  is  again  produced  by  the  great  con- 
traction at  the  Strait  of  Dover,  has  a  summer  tem- 
perature of  7°*5  C.  The  path  of  the  cold  indraught 
from  Spitzbergen  may  be  readily  traced  on  the  map 
by  the  depressions  in  the  surface  isothermal  lines,  and 
in  dredging  by  the  abundance  of  gigantic  amphi- 
podous  and  isopodous  crustaceans,  and  other  well- 
known  Arctic  animal  forms. 

From  its  low  initial  velocity  the  Arctic  return 
current,  or  indraught,  must  doubtless  tend  slightly 
in  a  westerly  direction,  and  the  higher  specific  gravity 
of  the  cold  water  may  probably  even  more  power- 
fully lead  it  into  the  deepest  channels ;  or  possibly 
the  two  causes  may  combine,  and  in  the  course  of 
ages  the  currents  may  hollow  out  deep  south- 
westerly grooves.     At  all   events,  the  main  Arctic 


400  THE  DEPTHS  OF  THE  SEA.  [chap.  viit. 

return  currents  are  very  visible  on  the  chart  taking 
this  direction,  indicated  by  marked  deflections  of 
the  isothermal  lines.  The  most  marked  is  the 
Labrador  current,  which  passes  down  inside  the 
Gulf-stream  along  the  coasts  of  Carolina  and  New 
Jersey,  meeting  it  in  the  strange  abrupt  '  cold 
wall,'  dipping  under  it  as  it  issues  from  the  Gulf, 
coming  to  the  surface  again  on  the  other  side, 
and  a  portion  of  it  actually  passing,  under  the  Gulf- 
stream,  as  a  cold  counter-current  into  the  Gulf  of 
Mexico. 

Fifty  or  sixty  miles  out  from  the  west  coast  of 
Scotland,  I  believe  the  Gulf-stream  forms  another, 
though  a  very  mitigated,  *cold  wall.'  In  1868, 
after  our  first  investigation  of  the  very  remarkable 
cold  indraught  into  the  channel  between  Shetland  and 
Fseroe,  I  stated  my  belief  that  the  current  was  entirely 
banked  up  in  the  Fseroe  Channel  by  the  Gulf-stream 
passing  its  gorge.  Since  that  time  I  have  been  led 
to  suspect  that  a  part  of  the  Arctic  water  oozes  down 
the  Scottish  coast,  much  mixed,  and  sufficiently 
shallow  to  be  affected  throughout  by  solar  radiation. 
About  sixty  or  seventy  miles  from  shore  the  isother- 
mal lines  have  a  slight  but  uniform  deflection. 
Within  that  line  types  characteristic  of  the  Scandi- 
navian fauna  are  numerous  in  shallow  water,  and 
in  the  course  of  many  years'  use  of  the  towing  net 
I  have  never  met  with  any  of  the  Gulf- stream 
pteropods,  or  of  the  lovely  Polycystina  and  Acantho- 
metrina  which  absolutely  swarm  beyond  that  limit. 
The  diflPerence  in  mean  temperature  between  the 
east  and  west  coasts  of  Scotland,  amounting  to 
about   1°C.,  is  also   somewhat   less   than  might  be 


ii 


CHAP,  viii.j  THE  OULF-STREAM.  401 

expected  if  the  Gulf-stream  came  close  to  the  western 
shore. 

While  the  communication  between  the  North 
Atlantic,  and  the  Arctic  Sea — itself  a  second  cul 
de  sac — is  thus  restricted,  limiting  the  interchange  of 
warm  and  cold  water  in  the  normal  direction  of  the 
flow  of  the  Gulf-stream,  and  causing  the  diversion  of 
a  large  part  of  the  stream  to  the  southwards,  the 
communication  with  the  Antarctic  basin  is  as  open  as 
the  day ; — a  continuous  and  wide  valley  upwards  of 
2,000  fathoms  in  depth  stretching  northwards  along 
the  western  coasts  of  Africa  and  Europe. 

That  the  southern  water  wells  up  into  this  valley 
there  could  be  little  doubt  from  the  form  of  the 
ground;  but  here  again  we  have  curious  corroborative 
evidence  on  the  map  in  the  remarkable  reversal  of  the 
curves  of  the  isotherms.  The  temperature  of  the  bot- 
tom water  at  1,230  fathoms  off  Uockall  is  3°-22  C, 
exactly  the  same  as  that  of  water  at  the  same  depth  in 
the  serial  sounding,  lat.  47°  38'  N.,  long.  12°  08' W.  in 
the  Bay  of  Biscay,  which  affords  a  strong  presumption 
that  the  water  in  both  cases  is  derived  from  the  same 
source  ;  and  the  bottom  water  off  Bockall  is  warmer 
than  the  bottom  water  in  the  Bay  of  Biscay  (2°*5  C), 
while  a  cordon  of  temperature  soundings  drawn  from 
the  north-west  of  Scotland  to  a  point  on  the  Iceland 
shallow  gives  no  temperature  lower  than  6°-5  C.  This 
makes  it  very  improbable  that  the  low  temperature 
of  the  Bay  of  Biscay  is  due  to  any  considerable  por- 
tion of  the  Spitzbergen  current  passing  down  the  west 
coast  of  Scotland;  and  as  the  cold  current  to  the 
east  of  Iceland  passes  southwards  considerably  to  the 
westward,  as  indicated  on  the  map  by  the  successive 


402  THE  DEPTHS  OF  THE  SEA.  [chap.  viii. 

depressions  in  the  surface  isotherms,  the  balance  of 
probability  seems  to  be  in  favour  of  the  view  that  the 
conditions  of  temperature  and  the  slow  movement  of 
this  vast  mass  of  moderately  cold  water,  nearly  two 
statute  miles  in  depth,  are  to  be  referred  to  an 
Antarctic  rather  than  to  an  Arctic  origin. 

The  North  Atlantic  Ocean  seems  to  consist  first  of 
a  great  sheet  of  warm  water,  the  general  northerly 
reflux  of  the  equatorial  current.     Of  this  the  greater 
part  passes  through  the  Strait  of  ^Florida,  and  its 
north-easterly  flow  is  aided  and  maintained  by  the 
anti-trades,  the    whole   being   generally   called  the 
Gulf-stream.     This  layer  is  of  varying  depths,  ap- 
parently from  the  observatious  of  Captain  Chimmo 
and  others,  thinning  to  a  hundred  fathoms  or  so  in 
the  mid- Atlantic,  but  attaining  a  depth  of  700  to  800 
fathoms  off  the  west  coasts  of  Ireland  and  Spain. 
Secondly  of  a  '  stratum  of  intermixture '  which  ex- 
tends to  about  200  fathoms  in  the  Bay  of  Biscay, 
through  which  the  temperature  falls  rather  rapidly ; 
and  thirdly,  of  an  underlying  mass  of  cold  water, 
in  the  Bay  of  Biscay  1,500  fathoms  deep,  derived  as 
an   indraught   falling   in   by    gravitation   from    the 
deepest  available  source,  whether  Arctic  or  Antarctic. 
It    seems    at    first    sight    a    startling    suggestion, 
that  the  cold  water  filling  deep  ocean  valleys  in  the 
northern   hemisphere  may   be   partly   derived   from 
the   southern;    but  this  difficulty,  I   believe,  arises 
from  the  idea  that  there  is  a  kind  of  diaphragm  at 
the  equator  between  the  northern  and  southern  ocean 
basins,  one  of  the  many  misconceptions  which  follow 
in  the  train  of  a  notion  of  a  convective  circulation  in 
the  sea  similar  to  that  in  the  atmosphere.     There  is 


CHAP,  viii]  THE  GULF-STREAM.  403 

undoubtedly  a  gradual  elevation  of  an  intertropical 
belt  of  the  underlying  cold  water,  which  is  being 
raised  by  the  subsiding  of  still  colder  water  into  its 
bed  to  supply  the  place  of  the  water  removed  by  the 
equatorial  current  and  by  excessive  evaporation ;  but 
such  a  movement  must  be  widely  and   irregularly 
diffused  and  excessively  slow,  not  in  any  sense  com- 
parable with  the  diaphragm  produced  in  the  atmo- 
sphere by  the  rushing  upwards  of  the  north-east  and 
south-east  trade-winds  in  the  zone  of  calms.    Perhaps 
one  of  the  most  conclusive  proofs  of  the  extreme 
slowness  of  the  movement  of  the  deep  indraught  is 
the  nature  of  the  bottom.     Over  a  great  part  of  the 
floor  of  the  Atlantic  a  deposit  is  being  formed  of 
microscopic  shells.     These   with   their   living   inha- 
bitants differ  little  in  specific  weight  from  the  water 
itself,  and  form  a  creamy  flocculent  layer,  which  must 
be  at  once  removed  wherever  there  is  a  perceptible 
movement.      In  water   of    moderate   depth,   in   the 
course  of  any  of  the  currents,  this  deposit  is  entirely 
absent,  and  is  replaced  by  coarser  or  finer  gravel. 

It  is  only  on  the  surface  of  the  sea  that  a  line  is 
drawn  between  the  two  hemispheres  by  the  equatorial 
current,  whose  effect  in  shedding  a  vast  intertropical 
drift  of  water  on  either  side  as  it  breaks  against  the 
eastern  shores  of  equatorial  land  may  be  seen  at  a 
glance  on  the  most  elementary  physical  chart. 

The  Gulf-stream  loses  an  enormous  amount  of  heat 
in  its  northern  tour.  At  a  point  200  miles  west  of 
Ushant,  where  observations  at  the  greatest  depths 
were  made  on  board  the  '  Porcupine,'  a  section  of 
the  water  of  the  i^tlantic  shows  three  surfaces  at 
which   interchange  of  temperature  is  taking   place. 

DD  2 


404  THE  DEPTHS  OF  THE  SEA.  fcHAP.  viii. 

Eirst,  the  surface  of  the  sea — that  is  to  say,  the 
upper  surface  of  the  Gulf-stream  layer — is  losing 
heat  rapidly  by  radiation,  by  contact  with  a  layer  of 
air  which  is  in  constant  motion  and  being  per- 
petually cooled  by  convection,  and  by  the  con- 
version of  water  into  vapour.  ^  As  this  cooling  of 
the  Gulf-stream  layer  takes  place  principally  at  the 
surface,  the  temperature  of  the  mass  is  kept  pretty 
uniform  by  convection.  Secondly,  the  band  of  con- 
tact of  the  lower  surface  of  the  Gulf-stream  water 
with  the  upper  surface  of  the  cold  indraught.  Here 
the  interchange  of  temperature  must  be  very  slow, 
though  that  it  does  take  place  is  shown  by  the 
slight  depression  of  the  surface  isotherms  over  the  I 
principal  paths  of  the  indraught.  But  there  is  a 
good  deal  of  intermixture  extending  through  a  con- 
siderable layer.  The  cold  water  being  beneath, 
convection  in  the  ordinary  sense  cannot  occur,  and 
interchange  of  temperature  must  depend  mainly  j 
upon  conduction  and  diffusion,  causes  which  in  the  \ 
case  of  masses  of  water  must  be  almost  secular  in 
their  action,  and  probably  to  a  much  greater  extent 
upon  mixture  produced  by  local  currents  and  by 
the  tides.  The  third  surface  is  that  of  contact  be- 
tween the  cold  indraught  and  the  bottom  of  the 
sea.  The  temperature  of  the  crust  of  the  earth 
has  been  variously  calculated  at  from  4°  to  11°  C, 
but  it  must  be  completely  cooled  down  by  anything 
like  a  movement  and  constant  renewal  of  cold  water. 

^  On  Deep-sea  Climates.  The  Substance  of  a  Lecture  delivered  to 
the  Natural  Science  Class  in  Queen's  College,  Eelfast,  at  the  close  of 
the  Summer  Session  1870,  by  Professor  Wyville  Thomson.  (^Naturey 
July  28th,  1870.) 


CHAP,  viii]  THE  GULF-STREAM.  405 

All  we  can  say,  therefore,  is  that  contact  with  the 
hottom  can  never  be  a  source  of  depression  of  tem- 
perature. As  a  general  result  the  Gulf-stream  water 
is  nearly  uniform  in  temperature  throughout  the 
greater  part  of  its  depth ;  there  is  a  marked  zone 
of  intermixture  at  the  junction  between  the  warm 
water  and  the  cold,  and  the  water  of  the  cold 
indraught  is  regularly  stratified  by  gravitation ; 
so  that  in  deep  water  the  contour  lines  of  the 
sea-bottom  are,  speaking  generally,  lines  of  equal 
temperature.  Keeping  in  view  the  enormous  in- 
fluence which  ocean  currents  exercise  in  the  dis- 
tribution of  climates  at  the  present  time,  I  think 
it  is  scarcely  going  too  far  to  suppose  that  such 
currents — movements  communicated  to  the  water  by 
constant  winds — existed  at  all  geological  periods  as 
the  great  means,  I  had  almost  said  the  sole  means, 
of  producing  a  general  oceanic  circulation,  and  thus 
distributing  heat  in  the  ocean.  They  must  have 
existed,  in  fact,  wherever  equatorial  land  inter- 
rupted the  path  of  the  drift  of  the  trade-winds. 
Wherever  a  warm  current  was  deflected  to  north 
or  south  from  the  equatorial  belt  a  polar  indraught 
crept  in  beneath  to  supply  its  place ;  and  the  ocean 
consequently  consisted,  as  in  the  Atlantic  and 
doubtless  in  the  Pacific  at  the  present  day,  of  an 
upper  warm  stratum,  and  a  lower  layer  of  cold 
water  becoming  gradually  colder  with  increasing 
depth. 

I  fear,  then,  that  in  opposition  to  the  views  of 
my  distinguished  colleague,  I  must  repeat  that  I 
have  seen  as  yet  no  reason  to  modify  the  opinion 
which  I  have  consistently  held  from  the  first,  that 


406 


THE  DEPTHS  OF  THE  SEA. 


[chap.  VIII. 


the  remarkable  conditions  of  climate  on  the  coasts 
of  Northern  Europe  are  due  in  a  broad  sense  solely 
to  the  Gulf-stream.  That  is  to  say,  that  although 
movements,  some  of  them  possibly  of  considerable 
importance,  must  be  produced  by  differences  of  spe- 
cific gravity,  yet  the  influence  of  the  great  current 
which  we  call  the  Gulf-stream,  the  reflux  of  the 
great  equatorial  current,  is  so  paramount  as  to  reduce 
all  other  causes  to  utter  insignificance. 


THE    GIANT    ANO   TUK    HAG. 


CHAPTER  IX. 

THE    DEEP-SEA    FAUNA. 

The  Protozoa  of  the  Deep-sea. — BathyUus. — *  Coccoliths,'  and  *  Cocco- 
spheres.' — The  Foraminifera  of  the  Warm  and  Cold  Areas. — Deep- 
sea  Sponges.  —  The  Hexactinellidae. — Rossella. — Hyalonema. — 
Deep-sea  Corals. — The  Stalked  Crinoids. — Fentacrinus. — Rhizo- 
crinus.  —  Balhycrimis.  —  The  Star- fishes  of  the  Deep-sea. — The 
general  Distribution  and  Eelations  of  Deep-sea  Urchins. — The 
Crustacea,  the  Mollusca,  and  the  Fishes  of  the  '  Porcupine '  Expe- 
ditions. 

The  time  has  not  yet  arrived  for  giving  anything 
like  a  detailed  account  of  the  deep-sea  fauna;  even 
if  it  were  possible  to  do  so  in  a  popular  sketch  of 
the  general  results  of  a  wide  investigation.  I  must 
therefore  confine  myself  at  present  to  a  brief  outline 
of  the  distribution  of  the  forms  of  animal  life  which 
were  met  with  in  the  belt  partially  examined  during 
the  '  Porcupine  '  dredgings,  a  belt  which  carries  the 
British  zoological  area  about  a  hundred  miles  further 
out  to  seaward  along  the  northern  and  western  coasts 
of  the  British  Isles,  and  into  depths  extending  from 
200  fathoms,  the  previous  limit  of  accurate  know- 
ledge, to  800  and  1,000  fathoms,  and  in  one  or  two 
instances  to  the  extreme  depth  of  upwards  of  2,000 
fathoms. 


408  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

The  remarkable  general  result  that  even  to  these 
great  depths  the  fauna  is  varied  and  rich  in  all  the 
marine  invertebrate  groups,  has  inundated  us  with 
new  material  which  in  several  of  the  larger  depart- 
ments it  will  take  years  of  the  labour  of  specialists 
to  work  up.  While  referring  very  briefly  to  those 
orders  which  it  has  been  found  impossible  as  yet  to 
overtake,  I  will  enter  a  little  more  fully  into  the 
history  of  certain  restricted  groups  which  more  par- 
ticularly illustrate  the  conditions  of  the  abyssal 
region,  and  the  relations  of  its  special  fauna  to  the 
faunae  of  other  zoological  provinces,  or  to  those  of 
earlier  times.  And  very  prominent  among  these 
special  groups  we  find  the  first  and  simplest  of  the  in- 
vertebrate sub-kingdoms,  the  Protozoa,  represented 
by  three  of  its  classes, — the  monera,  the  rhizopoda, 
and  the  sponges. 

The  monera  have  been  lately  defined  as  a  distinct 
class  by  Professor  Ernst  Haeckel,^  for  a  vast  assem- 
blage of  almost  formless  beings,  apparently  abso- 
lutely devoid  of  internal  structure,  and  consisting 
simply  of  living  and  moving  expansions  of  jelly-like 
protoplasm;  and  although  the  special  character  on 
which  Haeckel  separates  them  from  the  remainder  of 
the  protozoa, — that  they  are  propagated  by  no  form 
of  sexual  reproduction,  but  simply  by  spontaneous 
division, — may  probably  prove  deceptive  as  our  know- 
ledge increases,  still  their  number,  their  general 
resemblance  to  one  another,  presenting  obviously 
different  and  recognizable  kinds  although  with  very 
indefinable  characters,  and  the  important  part  which 

^  Biologische  Studien.  Yon  Dr.  Ernst  Haeckel,  Professor  an  der 
Universitilt  Jena.     Leipzig,  1870. 


CHAP.  IX.]  THE  DEEP-SEA  FAUNA.  409 

they  play  in  the  economy  of  nature,  would  seem  to 
entitle  them  to  a  systematic  position  of  more  than 
ordinal  value.  The  German  naturalists  of  the  new 
school,  in  their  enthusiastic  adoption  of  the  Dar- 
winian theory  of  evolution,  naturally  welcome  in 
these  '  moners '  the  essential  attribute  of  the  *  Ur- 
schleim,'  an  infinite  capacity  for  improvement  in 
every  conceivable  direction  ;  and  to  more  prosaic 
physiologists  they  are  of  the  deepest  interest,  as 
presenting  the  essential  phenomena  of  life,  nutri- 
tion and  irritability,  existing  apparently  simply  as 
the  properties  of  a  homogeneous  chemical  compound, 
and  independent  of  organization. 

The  monera  pass  into  the  rhizopoda,  which  give 
a  slight  indication  of  advance,  in  the  definite  form 
of  the  graceful  calcareous  shell-like  structures  which 
most  of  them  secrete,  and  the  two  groups  may  be 
taken  together. 

The  dredging  at  2,435  fathoms  at  the  mouth  of 
the  Bay  of  Biscay  gave  a  very  fair  idea  of  the  con- 
dition of  the  bottom  of  the  sea  over  an  enormous 
area,  as  we  know  from  many  observations  which 
have  now  been  made,  with  the  various  sounding 
instruments  contrived  to  bring  up  a  sample  of  the 
bottom.  On  that  occasion  the  dredge  brought  up 
about  1^  cwt.  of  calcareous  mud.  There  could  be 
little  doubt,  from  the  appearance  of  the  contents  of 
the  dredge,  that  the  heavy  dredge-frame  had  gone 
down  wdth  a  plunge,  and  partly  buried  itself  in 
the  soft,  yielding  bottom.  The  throat  of  the  dredge 
thus  became  partly  choked,  and  the  free  entrance 
of  the  organisms  on  the  sea-floor  had  been  thus 
prevented.     The  matter  contained  in  the  dredge  con- 


410  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

sisted  mainly  of  a  compact  'mortar,'  of  a  bluisli 
colour,  passing  into  a  thin — evidently  superficial — 
layer,  much  softer  and  more  creamy  in  consistence, 
and  of  a  yellowish  colour.  Under  the  microscope  the 
surface-layer  was  found  to  consist  chiefly  of  entire 
shells  of  GloUgerina  bulloides  (Fig.  2,  p.  22),  large 
and  small,  and  fragments  of  such  shells  mixed 
with  a  quantity  of  amorphous  calcareous  matter  in 
fine  particles,  a  little  fine  sand,  and  many  spicules, 
portions  of  spicules,  and  shells  of  Radiolaria,  a  few 
spicules  of  sponges,  and  a  few  frustules  of  diatoms. 
Below  the  surface-layer  the  sediment  becomes 
gradually  more  compact,  and  a  slight  grey  colour, 
due  probably  to  the  decomposing  organic  matter, 
becomes  more  pronounced,  while  perfect  shells  of 
globigerina  almost  entirely  disappear,  fragments  be- 
come smaller,  and  calcareous  mud,  structureless  and  in 
a  fine  state  of  division,  is  in  greatly  preponderating 
proportion.  One  can  have  no  doubt,  on  examining 
this  sediment,  that  it  is  formed  in  the  main  by  the 
accumulation  and  disintegration  of  the  shells  of 
globigerina — the  shells  fresh,  whole,  and  living  in 
the  surface-layer  of  the  deposit,  and  in  the  lower 
layers  dead,  and  gradually  crumbling  down  by  the 
decomposition  of  their  organic  cement,  and  by  the 
pressure  of  the  layers  above — an  animal  formation 
in  fact  being  formed  very  much  in  the  same  way  as  in 
the  accumulation  of  vegetable  matter  in  a  peat  bog, 
by  life  and  growth  above,  and  death,  retarded  de- 
composition, and  compression  beneath. 

In  this  dredging,  as  in  most  others  in  the  bed 
of  the  Atlantic,  there  was  evidence  of  a  considerable 
quantity  of  soft  gelatinous  organic  matter,  enough 


CHAP.  IX.]  THE  DEEP-SEA  FAUNA.  411 

to  give  a  slight  viscosity  to  the  mud  of  the  surface 
layer.  If  the  mud  be  shaken  with  weak  spirit  of 
wine,  fine  flakes  separate  like  coagulated  mucue ; 
and  if  a  little  of  the  mud  in  which  this  viscid  con- 
dition is  most  marked  be  placed  in  a  drop  of  sea- 
water  under  the  microscope,  we  can  usually  see, 
after  a  time,  an  irregular  network  of  matter  resem- 
bling white  of  e^^,  distinguishable  by  its  maintaining 
its  outline  and  not  mixing  with  the  water.  This 
network  may  be  seen  gradually  altering  in  form,  and 
entangled  granules  and  foreign  bodies  change  their 
relative  positions.  The  gelatinous  matter  is  therefore 
capable  of  a  certain  amount  of  movement,  and  there 
can  be  no  doubt  that  it  manifests  the  phenomena  of 
a  very  simple  form  of  life. 

To  this  organism,  if  a  being  can  be  so  called  which 
shows  no  trace  of  differentiation  of  organs,  consist- 
ing apparently  of  an  amorphous  sheet  of  a  protein 
compound,  irritable  to  a  low  degree  and  capable  of 
assimilating  food.  Professor  Huxley  has  given  the 
name  of  Bathyhius  haeckelii  (Fig.  63).  If  this  have  a 
claim  to  be  recognized  as  a  distinct  living  entity,  ex- 
hibiting its  mature  and  final  form,  it  must  be  referred 
to  the  simplest  division  of  the  shell-less  rhizopoda,  or 
if  we  adopt  the  class  proposed  by  Professor  Haeckel, 
to  the  monera.  The  circumstance  which  gives  its 
special  interest  to  Bathyhius  is  its  enormous  extent : 
whether  it  be  continuous  in  one  vast  sheet,  or  broken 
up  into  circumscribed  individual  particles,  it  appears 
to  extend  over  a  large  part  of  the  bed  of  the  ocean ; 
and  as  no  living  thing,  however  slowly  it  may  live, 
is  ever  perfectly  at  rest,  but  is  continually  acting  and 
reacting  with   its  surroundings,  the  bottom  of  the 


412 


THE  DEPTHS  OF  THE  SEA. 


[chap.  IX. 


sea  becomes  like  the  surface  of  the  sea  and  of  the 
land, — a  theatre  of  change,  performing  its  part  in 
maintaining  the  *  balance  of  organic  nature.' 


Fig.  63.— "Eine  grossere  Cytode  von  Bathybius  mit  eingebettetcti  Coccolithen.  Das  Proto- 
plasma,  welches  viele  Discolithen  und  Cyatholithen  enthiilt,  bildet  ein  Netzwerk  niit  breiten 
Strangen.'   (x.  700.  )i 

1  Biologische  Studien.    Von  Dr.  Ernst  Haeckel,  Professor  an  der 
Universitat  Jena.     Leipzig,  1870. 


CHAP.  IX.]  THE  DEEP-SEA  FAUNA.  413 

Entangled  and  borne  along  in  the  viscid  streams 
of  Bathybius,  we  so  constantly  find  a  multitude  of 
minute  calcareous  bodies  of  a  peculiar  shape,  that 
the  two  were  for  long  supposed  to  have  some 
mutual  relation  to  one  another.  These  small  bodies, 
which  have  been  carefully  studied  by  Huxley,^ 
Sorby,2  Haeckel,^  Carter,*  Giimbel,^  and  others,  are 
in  shape  somewhat  like  oval  shirt-studs.  There  is 
first  a  little  oval  disk  about  0*01  mm.  in  length,  with 
an  oblong  rudely  facetted  elevation  in  the  centre, 
and  round  that,  in  fresh  sjjecimens,  what  seems  to  be 
a  kind  of  frill  of  organic  matter,  then  a  short  neck, 
and  lastly  a  second  smaller  flat  disk,  like  the  disk 
at  the  back  of  a  stud.  To  these  bodies,  which  are 
met  with  in  all  stages  of  development,  Professor 
Huxley  has  given  the  name  of  '  coccoliths.'  Some- 
times they  are  found  aggregated  on  the  surface  of 
small  transparent  membranous  balls,  and  these 
which  seemed  at  first  to  have  something  to  do  with 
the  production  of  the  '  coccoliths '  Dr.  Wallich  has 
called  '  coccospheres '  (Fig.  64).  Professor  Ernst 
Haeckel  has  lately  described  a  very  elegant  organ- 
ism belonging  to  the  radiolaria  and  apparently 
allied  to  Thalassicolla, — MyxohracMa  rhopalum, — and 
at  the  ends  of  some  curious  diverging  appendages 
of  this  creature  he  has  detected  accumulations  of 
bodies  closely  resembling,  if  not  identical  with,  the 
coccoliths  and  coccospheres  of  the  sea-bottom.     These 

^  Quarterly  Journal  of  Microscopical  Science,  1868,  p.  203. 
2  Proceedings  of  the  Sheffield  Literary  and  Philosophical  Society, 
October  1860.  'Op.  cit. 

*  Ann.  and  Mag.  Nat.  Hist.  1871,  p.  184. 
^  Jalirbuch  Miinch.   1870,  p.  75.3. 


414  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

bodies  seem  to  have  been  taken  in  to  the  Myxo- 
brachia  as  food,  the  hard  parts  accumulating  in 
cavities  in  the  animal's  body  after  all  the  available 
nourishment  had  been  absorbed.  It  is  undoubted 
that  a  large  number  of  the  organisms  whose  skele- 
tons are  mixed  with  the  ooze  of  the  bottom  of  the 
sea  live  on  the  surface,  the  delicate  silicious  or  cal- 
careous shields  or  spines  falling  gradually  through 


Fig.  64.— 'Coccosphere.'    (x.  1000.) 


the  water  and  finally  reaching  the  bottom,  what- 
ever be  the  depth.  I  think  that  now  the  balance  of 
opinion  is  in  favour  of  the  view  that  the  coccoliths 
are  joints  of  a  minute  unicellular  alga  living  on  the 
sea-surface  and  sinking  down  and  mixing  with  the 
sarcode  of  Bathyhius^  very  probably  taken  into  it  with 
a  purpose,  for  the  sake  of  the  vegetable  matter 
they  may  contain,  and  which  may  afford  food  for 
the  animal  jelly.     What  the  coccospheres  are,  and 


CHAP.  IX.]  THE  DEEP-SEA  FAUNA.  415 

what  relation,  if  any,  they  have  to  the  coccoliths, 
we  do  not  know. 

Living  upon  and  among  this  JBathyhius^  we  find 
a  multitude  of  other  protozoa, — foraminifera  and 
other  rhizopods,  radiolarians,  and  sponges;  and  we 
as  yet  know  very  little  of  the  life-history  of  these 
groups.  There  can  be  no  doubt  that  when  their 
development  has  been  fully  traced  many  of  them 
will  be  found  to  be  di-  or  poly-morphic,  and  that 
when  we  are  acquainted  with  their  mode  of  multi- 
plication we  shall  meet  with  many  cases  of  pleo- 
morphism  and  wide  differences  between  the  organs 
and  products  involved  in  propagation  and  in  repro- 
duction. I  feel  by  no  means  satisfied  that  Bathyhitis 
is  the  permanent  form  of  any  distinct  living  being. 
It  has  seemed  to  me  that  different  samples  have  been 
different  in  appearance  and  consistence;  and  although 
there  is  nothing  at  all  improbable  in  the  abundance 
of  a  very  simple  shell-less  *moner'  at  the  bottom 
of  the  sea,  I  think  it  not  impossible  that  a  great 
deal  of  the  'bathybius,'  that  is  to  say  the  diffused 
formless  protoplasm  which  we  find  at  great  depths, 
may  be  a  kind  of  mycelium — a  formless  condition 
connected  either  with  the  growth  and  multiplication 
or  with  the  decay — of  many  different  things. 

Many  foraminifera  of  different  groups  inhabit 
the  deep  water,  lying  upon  or  mixed  in  the  upper 
layer  of  the  globigerina  ooze,  or  fixed  to  some  foreign 
body,  such  as  a  sponge,  coral,  or  stone;  and  all  of 
these  are  remarkable  for  their  large  size.  In  the 
'warm  area,'  and  wherever  the  bottom  is  covered  with 
ooze,  calcareous  forms  jpredominate,  and  large  sandy 
cristellarians,  with  their  sand-grains  bound  together 


416  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

by  calcareous  cement,  so  that  the  sand-grains  show 
out,  dark  and  conspicuous,  scattered  on  the  surface 
of  the  white  shell.  Miliolines  are  abundant,  and 
the  specimens  of  Cornus]^ira  and  Biloculina  are 
greatly  larger  than  anything  which  has  been  hitherto 
met  with  in  temperate  regions,  recalling  the  tropical 
forms  which  abound  among  the  Pacific  Islands. 

In  the  cold  area,  and  in  the  paths  of  cold  currents, 
foraminifera  with  sandy  tests  are  more  numerous; 
some  of  those  of  the  genera  Astrorhiza,  Lituola, 
and  Botellina  are  gigantic — large  examples  30  mm. 
long  by  8  mm.  in  diameter. 

The  few  hauls  of  the  dredge  which  we  have  already 
had  in  deep  water  have  been  enough  to  teach  us  that 
our  knowledge  of  sponges  is  in  its  infancy, — that  those 
which  we  have  collected  from  shallow  water  along 
our  shores,  and  even  those  few  which  have  been 
brought  up  from  deep  water  on  fishing  lines,  and 
have  surprised  us  by  the  beauty  of  their  forms  and 
the  delicacy  of  their  lustre,  are  the  mere  margin  and 
remnant  of  a  wonderfully  diversified  sponge-fauna 
which  appears  to  extend  in  endless  variety  over  the 
whole  of  the  bottom  of  the  sea.  I  cannot  attempt 
here  more  than  a  mere  outline  of  the  general  cha- 
racter of  the  additions  which  have  been  made  to  our 
knowledge  of  this  group.  The  sponges  of  the  '  Por- 
cupine' Expedition  are  now  in  the  hands  of  Mr. 
Henry  Carter,  P.R.S.,  for  description;  and  an  ex- 
cellent sketch  of  the  sponge-fauna  of  the  deep  Atlan- 
tic, bringing  information  on  certain  groups  up  to  a 
late  date,  has  been  published  by  the  best  authority 
we  have  on  sponges,  Professor  Oscar  Schmidt  of 
Gratz. 


CHAP.  VII.]  THE  DEEP-SEA  FAUNA.  417 

As  I  have  already  said,  the  most  remarkable  new 
forms  are  referable  to  the  group  which  seems  to  be, 
in  a  sense  special  to  deep  water,  the  Hexactinellidae. 
I  have  already  (p.  70)  briefly  described  one  of  the 
most  abundant  and  singular  forms  belonging  to  this 
order,    Holtenia    carpenteri ;    and     all    the    others, 
though  running  through  most  remarkable  variations 
in  form  and  general  appearance,  agree  with  Holtenia 
in  essential  structure.     In  the  Hexactinellidse  all  the 
spicules,  so  far  as  we  know,  are  formed  on  the  hex- 
radiate  plan ;  that  is  to  say,  there  is  a  primary  axis, 
which  may  be  long  or  short,  and  at  one  point  four 
secondary  rays  cross  this  central  shaft  at  right  angles. 
Very  often  one-half  of  the  central  shaft  is  absent  or 
is  represented  by  a  slight  rounded  boss,  and  in  that 
case  we  have  a  spicule  with  a  cross-shaped  head,  a 
very  favourite  form  in  the  manufacture,  defence,  and 
ornament  of  the  surface  layer  of  these  sponges ;  and 
often   the   secondary  rays   are  undeveloped :    but   if 
that   be   so, — as   in   the   long    fibres   of    the   whisp 
of   Hyalonema, — in  young    spicules    and    in    others 
which  are   slightly  abnormal,  four  little  elevations 
near  the  middle  of  the  spicule,  which  contain  four 
secondary  branches  of  the  central  canal,  maintain  the 
oermanence  of  the  type.      In  many  of  the  Hexac- 
inellidse  the  spicules  are  all  distinct,  and  combined, 
is  in  Holtenia,  by  a  small  quantity  of  nearly  trans- 
»arent  sarcode ;  but  in  others,  as  in  '  Venus's  flbwer- 
asket,'   and   the    nearly    equally    beautiful    genera 
phiteon,   Aphrocallistes,    and   Farrea,   the    spicules 
an  together  and  make  a  continuous  silicious  net- 
ork.     When  this  is  the   case  the  sponge  may  be 
Diled  in  nitric  acid,  and  all  the  organic  matter  and 

E  E 


418  THi:  DEPTHS  OF  THE  SEA.  [chap.  vii. 

other  impurities  thus  removed,  when  the  skeleton 
comes  out  a  lovely  lacy  structure  of  the  clearest 
glass.  The  six-rayed  form  of  the  spicules  gives  the 
network  which  is  the  result  of  their  fusion  great 
flexibility  of  design,  with  a  characteristic  tendency, 
however,  to  square  meshes. 

On  the  30th  of  August,  1870,  Mr.  Gwyn  Jeffreys 
dredged  in  651  fathoms  in  the  Atlantic  off  the  mouth 
of  the    Strait   of    Gibraltar    an    exquisite    sponge, 
resembling  Holtenia  in  its  general  appearance,  but 
differing  from  it  in  the  singular  and  beautiful  cha- 
racter of  having  a  delicate  outer  veil  about  a  centi- 
metre from  the  surface  of  the  sponge,  formed  by  the 
interlacing  of  the  four  secondary  rays  of  large  five- 
rayed  spicules,  which  send  their  long  shafts  from  that 
point  vertically  into  the  sponge  body  (Fig.  65).    The 
surface  of  the  sponge  is  formed  of  a  network  of  large 
five-radiate  spicules,  arranged  very  much  as  in  Hol- 
tenia ;    but  the  spicules  of  the    sarcode — the  small 
spicules  which  are  imbedded  in  the  living  sponge-jelly 
— are  of  a  totally   different    form.     A   single   large 
*  osculum '   opens,  as  in  Holtenia,  at  the  top  of  the 
sponge,    but    instead    of   forming   a   cup    uniformly 
lined  with  a   netted   membrane,  the  oscular   cavity 
divides  at  the  bottom  into  a  number  of  branching 
passages  as  in  JPheronema   anncB,  described  by  Dr. 
Leidy.     I  was  inclined  at  first  to  place  this  species 
in  the  genus   'Pheronema,  but  Dr.   Leidy's  descrip- 
tion and  figure   are  by  no  means   satisfactory,  and 
may  refer  to  some  other  form  of  the  Holtenia  group. 
The  spicules  of  the  '  beard  '  are  more  rigid  and  thicker 
than  those  of  Holtenia,  and  scattered   among  them 
are  some  very  large  four-barbed  grappling  hooks. 


p 


CHAP.    VII.] 


THE  LEEP-SEA  FAUNA. 


419 


Fig.  iob.—Rossdla  veluta,  Wvvii.i.k  Thomson.     Natural  size.     (i:o.  3?,  1S70. ) 
E  E  2 


420  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

Off  the  Butt  of  the  Lews,  in  water  of  450  to  500 
fathoms,  we  met  on  two  occasions  with  full-grown 
specimens  of  a  species  of  the  remarkahle  genus 
Hyalonema  (Fig.  Q^),  Avith  the  coils  in  the  larger 
examples  upwards  of  40  centimetres  in  length. 
Hyalonema  is  certainly  a  very  striking  object;  and 
although  our  specimens  belong  apparently  to  the 
same  species,  K.  lusitanicum,  which  has  already  been  , 
recorded  by  Professor  Barboza  du  Bocage  from  the  | 
coast  of  Portugal,  it  is  one  of  the  most  interesting 
additions  made  to  the  British  fauna  during  our 
cruise. 

A  bundle  of  from  200  to  300  threads  of  trans- 
parent silica,  glistening  with  a  silky  lustre,  like  the 
most  brilliant  spun-glass, — each  thread  from  30  to  40 
centimetres  long,  in  the  middle  the  thickness  of  a 
knitting  needle,  and  gradually  tapering  towards  either    ._ 
end  to  a  fine  point ;    the  whole  bundle  coiled  like  a    I 
strand  of  rope  into  a  lengthened  spiral,  the  threads  of 
the  middle  and  upper  portions  remaining  compactly 
coiled  by  a  permanent  twist  of  the  individual  threads  ; 
the  lower  part  of  the  coil,  which,  when  the  sponge  is 
living,  is  imbedded  in  the  mud,  frayed  out  so  that  the 
glassy  threads  stand  separate  from  one  another,  like 
the  bristles  of  a  glittering  brush ;  the  upper  portion 
of  the  coil    close   and    compact,   imbedded  perpen- 
dicularly in   a   conical   or   cylindrical   sponge;    and 
usually  part  of  the  upper  portion  of  the   silicious  ) 
coil,    and  part    of  the    sponge  -  substance,    covered  • 
with  a  brownish  leatherv  coatinsr,  whose  surface  is 
studded  with  the  polyps  of  an  alcyonarian  zoophyte : 
— such  is  the  general  effect  of  a  complete  specimen 
of  Hyalonema, 


Pig.  66.~Hyalonema  lusitaninnn.  Barroza  du  Dotage     Half  the  natural 


size.     {No.  90.  1SC9. 


422  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

The  genus  was  first  known  in  Europe  by  specimens 
brought  from  Japan  by  the  celebrated  naturalist  and 
traveller,  Yon  Siebold;  and  Japanese  examples  of 
Hyaloiiema  sieboldi,  Gray,  may  now  be  found  more 
-or  less  perfect  in  most  of  the  European  museums. 
When  the  first  specimen  of  Hyalonema  was  brought 
home,  the  other  vitreous  sponges  which  approach  it 
so  closely  in  all  essential  points  of  structure  were 
unknown,  and  the  history  of  opinion  as  to  its  rela- 
tions is  curious.  I 

The  being  consisted  of  three  very  distinct  parts  : 
first,  and  greatly  the  most  remarkable,  the  coil 
of  silicious  needles  ;  then  the  sponge,  and  for  long 
it  was  supposed  that  this  was  the  base  of  the  struc- 
ture,— from  which  the  glossy  brush  projected,  spread- 
ing out  above  it  in  the  water  ;  and  thirdly,  the 
apparently  constant  encrusting  zoophyte. 

This  complicated  association  suggested  many  pos- 
sibilities. Was  Syalonema  a  natural  production  at 
all  ?  Was  it  complete  ?  Were  all  the  three  parts 
essentially  connected  together  ?  And  if  not,  were  all 
the  three  independent,  or  did  two  of  three  parts 
belong  to  the  same  thing  ?  and  if  so,  which  two  ? 

Hyalonema  was  first  described  and  named  in 
1835  by  Dr.  John  Edward  Gray,  who  has  since, 
in  one  or  two  notices  in  the  'Annals  of  Natural 
History'  and  elsewhere,  vigorously  defended  the 
essential  part  of  his  original  position.  Dr.  Gray 
associated  the  silicious  whisp  with  the  zoophyte, 
and  regarded  the  sponge  as  a  separate  organism. 
He  looked  upon  the  silicious  coil  as  the  representa- 
tive of  the  horny  axis  of  the  sea-fans  (GorgonicB), 
and  the  leather-like   coat  he  regarded  as  its  fleshy 


CHAP.  VII.}  THE  DEEP-SEA  FAUN  J,  493 

rind.  He  supposed  that  between  this  zoophyte  and 
the  sponge  at  its  base,  there  subsisted  a  relation  of 
guest  and  host,  the  zoophyte  being  constantly  asso- 
ciated with  the  sponge ;  and  in  accordance  with  this 
view  he  proposed  for  the  reception  of  the  zoophyte 
a  new  group  of  alcyonarians  under  the  name  of 
'Spongicolse,'  as  distinguished  from  the  'Sabulicolse' 
(Pennatulce)  and  the  '  Eupicolse '  {Gorgonice). 

Dr.  Gray's  view  seemed  in  many  respects  a  natural 
one,  and  it  was  adopted  in  the  main  by  Dr.  Brandt 
of  St.  Petersburg,  who  in  1859  published  a  long 
memoir,  describing  a  number  of  specimens  brought 
from  Japan  to  Russia.  Dr.  Brandt  referred  what  he 
believed  to  be  a  zoophyte  consisting  of  the  coil  and 
the  crust,  to  a  special  group  of  sclerobasic  zoanth- 
carians  with  a  silicious  axis. 

One  consideration  militated  strongly  against  this 
hypothesis  of  Dr.  Gray  and  Professor  Brandt.  No 
known  zoophyte  had  a  purely  silicious  axis;  and 
such  an  axis  made  up  of  loose  separate  spicules 
seemed  strangely  inconsistent  with  the  harmony  of 
the  class.  On  the  other  hand,  silicious  spicules  of 
all  forms  and  sizes  were  conceivable  in  sponges ; 
and  in  1857  Professor  Milne-Edwards,  on  the 
authority  of  Valenciennes,  who  was  thoroughly 
versed  in  the  structure  of  the  Gorgonice,  combined 
the  sponge  with  the  silicious  rope,  and  degraded  the 
zoophyte  to  the  rank  of  an  encrusting  parasite. 

Anything  very  strange  coming  from  Japan  is  to 
be  regarded  wdth  some  distrust.  The  Japanese  are 
wonderfully  ingenious,  and  one  favourite  aim  of 
their  misdirected  industry  is  the  fabrication  of  im- 
possible monsters  by  the  curious  combination  of  the 


424  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

parts  of  different  animals.     It  was  therefore  quite 
possible  that  the  whole  thing  might  he  an  imposi- 
tion :    that   some  beautiful   spicules   separated  from 
an  unknown  organism  had  been  twisted  into  a  whisp 
by   the  Japanese,  and   then   manipulated   so   as   to 
have  their  fibres   naturally  bound   together   by  the 
sponges  and  zoophytes  which  are  doubtless  rapidly 
developed  in  the  Mongolian  rock-pools.     Ehrenberg, 
when  he  examined  Hyalonema,  took  this  view.     He 
at  once  recognized  the  silicious  strands  as  the  spicules 
of  a  sponge  quite  independent  of  the  zoophyte  with 
which  they  were  encrusted ;  but  he  suggested  that 
these  might  have  been  artificially  combined  into  the 
spiral  coil  and  placed  under  artificial  circumstances 
favourable  to  the  growth  of  a  sponge  of  a  different 
species  round  their  base.      The  condition  in  which 
many  specimens  reach  Europe  is  certainly  calculated 
to  throw  some  doubt  on  their  genuineness.     It  seems 
that   the   bundles   of  spicules   made   up   in  various 
ways,  are  largely  sold   as  ornaments  in  China  and 
Japan.     The  coils  of  spicules  are  often  stuck  upright 
with  their  upper   ends   in   circular   holes  in  stones. 
Mr.    Huxley    exhibited    a    few    years    ago    at    the 
Linnaean  Society  a  beautiful  specimen  of  this  kind 
now  in  the    British   Museum: — a   stone    has   been 
bored,  probably  by  a  colony  of  boring  molluscs,  and 
a  whole  colony  of  Hyalonemas,  old  and  young,  are 
apparently  growing  out  of  the  burrows,  the  larger 
individuals   more    than   a    foot    in  length,  and  the 
young  ones  down  to  an  inch  or  so,  like  tiny  camel's- 
hair  pencils.     All  these  are  encrusted  by  the  usual 
zoophyte,  which   also   extends   here   and  there  over 
the  stone  (glued  on  probably),  but  there  is  no  trace 


CHAP.  VII.]  THE  DEEP-$IiA  VAVNA.  425 

of  the  sponge.     Such  an  association  is  undoubtedly 
artificial. 

Dr.  Bowerbank,  another  great  sponge  authority, 
takes  yet  another  view.  He  maintains  "that  the 
silicious  axis,  its  envelopment,  and  the  basal  sponge 
are  all  parts  of  the  same  animal."  The  polyps 
he  regards  as  '  oscula,'  forming  with  the  coil  a 
'  columnar  cloacal  system.' 

Professor  Max  Schultze,  of  Bonn,  examined  with 
great  care  several  perfect  and  imperfect  specimens  of 
Ryalonema  in  the  Museum  of  Ley  den,  and  in  1860 
published  an  elaborate  description  of  its  structure. 
According  to  Schultze,  the  conical  sponge  is  the 
body-mass  of  Hyalonema,  a  sponge  allied  in  every 
respect  to  Euplectella ;  and  the  siliceous  coil  is  an 
appendage  of  the  sponge  formed  of  modified  spicules. 
The  zoophyte  is  of  course  a  distinct  animal  altogether, 
and  its  only  connection  with  the  sponge  is  one  of 
'  commensalism.'  It  *  chums  '  with  the  sponge  for 
some  purpose  of  its  own, — certainly  getting  support 
from  the  coil,  probably  sharing  the  oxygen  and 
organic  matters  carried  in  by  the  ciliary  system  of 
the  sponge  passages.  This  style  of  association  is 
very  common.  We  have  another  example  of  the 
same  thing  in  Falythoa  axinellce,  Schmidt,  a  con- 
stant *  commensal '  with  Axinella  cinnamomea  and 
A,  verrucosa^  two  Adriatic  sponges. 

In  1864  Professor  Barboza  du  Bocage,  director 
of  the  Museum  of  Natural  History  in  Lisbon,  com- 
municated to  the  Zoological  Society  of  London  the 
unexpected  news  that  a  species  of  JSyalonema  had 
been  discovered  off  the  coast  of  Portugal ;  and  in  1865 
he  published,  in  the  Proceedings  of  the  same  Society, 


426  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

an  additional  note  on  the  habitat  of  Hyalonema  lusi- 
tamcum.  It  appears  that  the  fishermen  of  Setubal 
frequently  bring  up  on  their  lines,  from  a  consider- 
able depth,  coils  of  silicious  threads  closely  resem- 
bling those  of  the  Japanese  species,  which  they 
even  surpass  in  size,  sometimes  attaining  a  length  of 
about  50  centimetres.  The  fishermen  seem  to  be  very 
familiar  with  them.  They  call  them  '  sea-whips,' 
but  with  the  characteristic  superstition  of  their  class 
they  regard  all  these  extraneous  matters  as  '  unlucky,' 
and  usually  tear  them  in  pieces  and  throw  them 
into  the  water.  Judging  from  some  specimens  in 
the  British  Museum,  and  from  Senhor  du  Bocage's 
figure,  the  'glass-rope'  of  the  Portuguese  form  is 
not  so  thick  as  that  of  S.  sieboldi.  There  is  also 
some  slight  difference  in  the  sculpture  of  the  long 
needles,  but  the  structure  of  the  sponge  and  the  very 
characteristic  forms  of  the  small  spicules  are  identical 
in  the  two.  I  doubt  if  there  be  more  than  varietal 
distinctions  between  the  two  forms ;  and  if  that  be 
so,  it  adds  another  to  the  list  of  species  common  to 
our  seas  and  the  seas  of  Japan. 

Perhaps  the  most  singular  circumstance  connected 
with  this  discussion  was  that  all  this  time  we  had 
been  looking  at  the  sponge  upside  down,  and  that  it 
had  never  occurred  to  anyone  to  reverse  it.  We  had 
probably  taken  this  notion  from  the  specimens  stuck 
in  stones,  brought  from  Japan,  and  the  sponge  cer- 
tainly looked  very  like  the  base  of  the  edifice.  When- 
ever the  sponges  were  dredged  on  the  coasts  of  Europe 
and  compared  with  allied  things,  it  became  evident 
that  the  whisp  was  an  organ  of  support  passing  out 
of  the  lower  part  of  the  sponge,  and  that  the  flat, 


CHAP,  vii.]  TflE  DEEP-SEA  FAUNA.  427 

or  sliglitly-cupped  disk,  with  a  papilla  in  the  centre 
receiving  the  upper  end  of  the  coil,  with  large  oscular 
openings,  and  a  fringe  of  delicate  radiating  spicules 
round  the  edge,  was  the  top  of  the  sponge,  spreading 
out  probably  level  with  the  surface  of  the  ooze. 

In  essential  structure  Hyalonema  very  closely  re- 
sembles SoUenia,  and  the  more  characteristic  forms 
of  the  Hexactinellidae.  The  surface  of  the  sponge  is 
supported  by  a  square  network,  formed  by  the  sym- 
metrical arrangement  of  the  four  secondary  rays  of 
five-rayed  spicules,  and  the  sarcode  which  binds  these 
branches  together  is  full  of  minute  feathered  five- 
rayed  spicules,  which  project  from  the  branches  like 
a  delicate  fringe.  The  oscula  are  chiefly  on  the  upper 
disk,  and  lead  into  a  number  of  irregular  passages 
which  traverse  the  body  of  the  sponge  in  all  direc- 
tions. When  we  trace  its  development,  the  coil 
loses  its  mystery.  On  one  of  the  Holtenice  from  the 
Butt  of  the  Lews,  there  was  a  little  accumulation 
of  greenish  granular  matter  among  the  fibres.  On 
placing  this  under  the  microscope  it  turned  out  to 
be  a  number  of  very  young  sponges,  scarcely  out  of 
their  germ  state.  They  were  all  at  first  sight  very 
much  alike,  minute  pear-shaped  bodies,  with  a  long 
delicate  pencil  of  silky  spicules  taking  the  place  of 
the  pear-stalk.  On  closer  examination,  however,  these 
little  germs  proved  to  belong  to  different  species, 
each  showing  unmistakeably  the  characteristic  forms 
of  its  special  spicules.  Most  of  them  were  the  young 
of  Tisiphonia,  but  among  them  were  several  Holtenice, 
and  one  or  two  were  at  once  referred  to  Hyalonema. 
In  two  or  three  hauls  in  the  same  locality  we  got 
them   in   every    subsequent    stage — beautiful    little 


428  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

pear-shaped  things,  a  centimetre  long,  with  a  single 
osculum  at  the  top,  and  the  whisp  like  a  small 
brush.  At  this  stage  the  Falythoa  is  usually  absent, 
but  when  the  body  of  the  sponge  has  attained  15  mm. 
or  so  in  length  very  generally  a  little  pink  tubercle 
may  be  detected  at  the  point  of  junction  between 
the  sponge  body  and  the  coil,  the  germ  of  the  first 
polyp. 

Hyalonema  lusifanicum,  Barboza  du  Bocage,  the 
species  met  with  in  the  British  seas  and  along 
the  coast  of  western  Europe,  appears  to  be  local, 
but  very  abundant  at  the  stations  where  it  occurs. 
I  am  still  in  doubt  whether  we  are  to  regard  it 
as  identical  with  the  Japanese  species,  H.  sieboldi, 
Gray. 

During  Mr.  Gwyn  Jeffreys'  cruise  in  1870,  two 
specimens  of  a  wonderful  sponge  belonging  also  to  the 
Hexactinellidae  were  dredged  in  374  fathoms  in  rocky 
ground  off  Cape  St.  Vincent.  The  larger  of  these 
forms  a  complete  vase  oi*  a  very  elegant  form,  nearly 
ninety  centimetres  in  diameter  at  the  top  and  about 
sixty  in  height  (Fig.  67).  The  sponge  came  up  folded 
together,  and  had  much  the  appearance  of  a  piece 
of  coarse,  greyish-coloured  blanket.  Its  minute 
structure  is,  however,  very  beautiful.  It  consists, 
like  Holtenia,  of  two  netted  layers,  an  outer  and 
an  inner,  formed  by  the  symmetrical  interlacing  of 
the  four  cross  branches  of  five-rayed  spicules;  and, 
as  in  Holtenia  and  Bossella,  the  sarcode  is  full  of 
extremely  minute  five  and  six-rayed  spicules,  which, 
however,  have  a  thoroughly  distinct  character  of 
their  own,  with  here  and  there  a  very  beautiful 
rosette-like  spicule,  another  singular  modification  of 


CHAP.  vu.  THE  DEEP-SEA  FAUNA.  429 

the  hexradiate  type  characteristic  of  this  group. 
Between  the  two  netted  surfaces  the  sponge  sub- 
stance is  formed  of  loose  curving  meshes  of  loosely 
aggregated  bundles  of  long  simple  fibres,  sparsely 
mixed  with  spicules  of  other  forms.  This  sponge 
seems  to  live  fixed  to  a  stone.  There  are  no 
anchoring    spicules,    and    the   bottom    of    the   vase, 


Fig.  67. — Askoneina  setubalense,  Kent.     One-eighth  the  natural  size.    (No.  25,  1870.) 

which  in  our  two  specimens  is  a  good  deal  con- 
tracted and  has  a  square  shape  something  like  an 
jOld  Irish  'mether,'  has  apparently  been  torn  from 
some  attachment.  This  fine  species  was  named 
Askonema  setubalense,  and  very  briefly  described 
from  a  specimen  in  the  Lisbon  Museum  by  Mr. 
Saville  Kent,  in  a  paper  in  w^hich  he  noticed  some 


430  THE  DEPTHS  OF  THE  SEA.  [chap.  vir. 

*    the   sponges  dredged  from  Mr.  Marshall   Hall's 

acht.^ 
Sponges  belonging  to  other  groups  from  the  deep 
Avater    were    nearly    equally    interesting.      I    have 
already  alluded,  p.  188,  to  the  handsome  branching 

ponges  belonging  to  the  Esperadise,  which  abound 
off  the  coasts  of  Scotland  and  Portugal.  Near  the 
mouth  of  the  Strait  of  Gibraltar  a  number  of  species 
were  taken  in  considerable  quantity,  belonging  to  a 
group  which  were  at  first  confused  with  the  Ilexac- 
tinellidae,  on  account  of  their  frequently  forming  a 
similar  and  equally  beautiful  continuous  network  of 
silica,  so  as  to  assume  the  same  resemblance  to  deli- 
cate lace  when  boiled  in  nitric  acid.  The  Corallio- 
spongise  differ,  however,  from  the  Hexactinellidae  in 
one  very  fundamental  character.  While  in  the  latter 
the  spicule  is  hexradiate,  in  the  former  it  consists 
of  a  shaft  with  three  diverging  rays  at  one  end. 
These  frequently  spread  in  one  plane,  and  they  often 
re-divide,  and  frequently  the  spaces  between  them  are 
filled  up  with  a  secondary  expanse  of  silica,  variously 
frilled  and  netted  on  the  edge,  so  as  to  give  the  spicule 
the  appearance  of  an  ornamental  flat-headed  tack. 
These  three-rayed  stars  or  disks,  in  combination,  sup- 
port the  outer  membrane  of  sponges  of  this  order ; 
and  spicules  of  the  same  type,  fused  together  accord- 
ing to  various  plans,  form  the  sponge  skeleton. 

This  group  of  sponges  are  as  yet  imperfectly 
known.  They  seem  to  pass  into  such  forms  as 
Geodia  and  Tethya ;  and  the  typical  example  with 
which  we  are  most  familiar  is  the  genus  Dacty- 
localyx,  represented   by  the  cup-shaped  pumice-like 

1  Monthly  Microscopic  Journal,  November  1,  1870. 


CHAP,  vil]  the  DEEP-SEA  FAUNA.  431 

masses  which  are  thrown  ashore  from  time  to  time 
on  the  West  Indian  Islands. 

Professor  P.  Martin  Duncan  has  already  published 
an  account  of  the  stony  corals  (the  Madreporaria)  of 
the  cruise  of  the  '  Porcupine '  in  1869,  and  he  has 
now  in  hand  those  procured  off  the  coast  of  Portugal 
in  1870r  some  of  which  are  of  even  greater  interest 
from  their  close  resemblance  to  certain  cretaceous 
forms.  Twelve  species  of  stony  corals  were  dredged 
in  1869. 

Caryophyllia  borealis,  Pleming  (Pig.  4,  p.  27),  is 
very  abundant  at  moderate  depths,  particularly  along 
the  west  coast  of  Ireland,  where  many  varieties  are 
found.  The  greatest  depth  at  which  this  species  was 
dredged  is  705  fathoms.  It  is  found  fossil  in  the 
miocene  and  pliocene  beds  of  Sicily. 

Ceratocyathus  ornakis,  Seguenza. — Of  this  pretty 
coral  only  a  single  specimen  was  taken  in  705 
fathoms,  off  the  Butt  of  the  Lews.  It  had  not  pre- 
viously been  known  as  a  recent  species,  and  was 
described  by  Seguenza  from  the  Sicilian  miocene 
tertiaries.  Flabelliim  laciniatum,  Edwards  and 
Haime,  was  frequent  in  water  from  100  to  400 
fathoms,  from  Pgeroe  to  Cape  Clear.  Prom  the 
extreme  thinness  of  the  outer  crust,  this  coral  is 
excessively  brittle;  and  although  many  hundreds 
came  up  in  the  dredge,  scarcely  half-a-dozen  examples 
were  entire.  Another  fine  species  of  the  same  genus, 
Flahellum  distinctum  (Pig.  68),  was  dredged  on 
several  occasions  off  the  Portuguese  coast  in  IS 70. 
The  special  interest  attaching  to  this  species,  is 
that  it  appears  to  be  identical  with  a  form  living  in 
the  seas  of  Japan. 


432  THE  DEPTHS  OF  THE  SEA.  [chap.  vii. 

Lophohelia  prolifera,  Pallas  (Fig.  30,  p.  169). 
— Many  varieties ;  abundant  at  depths  from  150 
to  500  fathoms  all  along  the  west  coasts  of  Scot- 
land and  Ireland,  at  temperatures  varying  from 
0°  to  10°  C.  In  some  places, — as,  for  example,  at 
Station  54,  between  Scotland  and  Paferoe,  and  Station 
15,  between  the  west  coast  of  Ireland  and  the 
Porcupine  Bank, — there  seem  to  be  regular  banks 
of  it,  the  dredge  coming  up  loaded  with  fragments, 
living  and  dead. 

Pive  allied  species  of  the  genus  Amphihelia  oc- 
curred more  sparingly. 


Fio.  68.—Flabelhim  distinctum     Twice  the  natural  size.     (No.  28,  1870.) 

Allopora  oculina,  Ehrenberg,  a  very  beautiful 
form,  of  whicli  a  few  specimens  were  procured  in  the 
*cold  area,'  at  depths  a  little  over  300  fathoms. 

Thecopsammia  socialis,  Pourtales  (Pig.  69),  a  form 
closely  allied  to  Balanophyllia,  and  resembling  some 
crag  species.  It  had  been  previously  dredged  by 
Count  Pourtales  in  the  Gulf  of  Plorida.  Theco- 
psammia is  tolerably  common  in  deep  water  in  the 
'  cold  area,'  growing  in  patches,  five  or  six  examples 
sometimes  coming  up  on  one  stone. 


CHAP.    IX.] 


THE  DEEP-SEA  FAUNA. 


433 


I  have  already  adverted  to  the  danger  \^  e  run  in 
estimating  the  relative  proportions  in  vrhich  any 
special  groups  may  enter  into  the  sum  of  the  abyssal 
fauna,  by  the  proportion  in  Avhicli  they  are  recovered 
by  any  single  method  of  capture.  Prom  tlieir  con- 
siderable size,  the  length  and  rigidity  of  their  strag- 
gling rays,  and  their  habit  of  clinging  to  fixed  ob- 
jects, the  Echinodermata  are  not  very  readily  taken 


Fig.  69.— TAccopmrnmia  sodalis,  Pourtales.    Once  and  a  half  the  natural  size.  (No.  57  1869.) 


by  the  dredge,  but  they  fall  an  easy  prey  to  the 
*  hempen  tangles.'  It  is  possible  that  this  circum- 
stance may  to  a  certain  extent  exaggerate  their 
apparent  abundance  at  great  depths,  but  we  have 
direct  evidence  in  the  actual  numbers  which  are 
brought  up,  that  in  some  places  they  must  be  won- 

F  F 


434  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

derfully  numerous;  and  we  frequently  dredge  sponges 
and  corals  actually  covered  with  them  in  the  atti- 
tudes in  which  they  lived,  nestling  among  their  fibres 
and  in  the  angles  of  their  branches.  I  have  counted 
seventy- three  examples  of  Amphiura  abyssicola,  small 
and  large,  sticking  to  one  Holtenia. 

Both  on  account  of  their  beauty  and  extreme 
rarity,  and  of  the  important  part  they  have  borne 
in  the  fauna  of  some  of  the  past  periods  of  the 
earth's  history,  the  first  order  of  the  Echinoderms, 
the  Crinoidea,  has  always  had  a  special  interest  to 
naturalists;  and,  on  the  watch  as  we  were  for 
missing  links  which  might  connect  the  present  with 
the  past,  we  eagerly  welcomed  any  indication  of  their 
presence.  Crinoids  were  very  abundant  in  the  seas 
of  the  Silurian  period;  deep  beds  of  carboniferous 
limestone  are  often  formed  by  the  accumulation  of 
little  else  than  their  skeletons,  the  stem  joints  and 
cups  cemented  together  by  limy  sedimeAt;  and 
dozens  of  the  perfect  crowns  of  the  elegant  lily- 
encrinite  are  often  scattered  over  the  surface  of 
slabs  of  the  muschelkalk.  But  during  the  lapse  of 
ages  the  whole  order  seems  to  have  been  worsted 
in  the  '  struggle  for  life.'  They  become  scarce  in  the 
newer  mezozoic  beds,  still  scarcer  in  the  tertiaries, 
and  up  to  within  the  last  few  years  only  two 
living  stalked  crinoids  were  known  in  the  seas 
of  the  present  period,  and  these  appeared  to  be 
confined  to  deep  water  in  the  seas  of  the  Antilles, 
whence  fishermen  from  time  to  time  bring  up  muti- 
lated specimens  on  their  lines.  Their  existence  has 
been  known  for  more  than  a  century ;  but  although 
many  eyes  have  been  watching  for  them,  until  very 


CHVP.  IX.]  THE  DEEP-SEA  FAUNA.  4:^5 

lately  not  more  than  twenty  specimens  had  reached 
Europe,  and  of  these  only  two  showed  all  the  joints 
and  plates  of  the  skeleton,  and  the  soft  parts  were 
lost  in  all. 

These  two  species  helong  to  the  genus  JPentacrmus, 
which  is  well  represented  in  the  beds  of  the  lias  and 
oolite,  and  sparingly  in  the  white  chalk;  and  are 
named  respectively  Fentacritius  asteria,  L.,  and  P. 
millleri.  Oersted.  Eig.  70  represents  the  first  of  thcFe. 
This  species  has  been  known  in  Europe  since  the  year 
1755,  when  a  specimen  was  brought  to  Paris  from 
the  island  of  Martinique,  and  described  by  Guettard 
in  the  Memoirs  of  the  Hoyal  Academy  of  Sciences. 
Eor  the  next  hundred  years  an  example  turned  up 
now  and  then  from  the  Antilles.  Ellis  described 
one,  now  in  the  Hunterian  Museum  in  Glasgow 
University,  in  the  Philosophical  Transactions  for 
1761.  One  or  two  found  their  way  into  the  museums 
of  Copenhagen,  Bristol,  and  Paris ;  two  into  the 
British  Museum;  and  one  fortunately  fell  into  the 
hands  of  the  late  Professor  Johannes  Mtiller  of 
Berlin,  who  published  an  elaborate  account  of  it  in 
the  Transactions  of  the  Royal  Berlin  Academy  for 
1843.  Within  the  last  few  years,  Mr.  Damon  of 
Weymouth,  a  well-known  collector  of  natural  his- 
tory objects,  has  procured  several  very  good  speci- 
mens, which  are  now  lodged  in  the  museums  of 
Moscow,  Melbourne,  Liverpool,  and  London. 

Fentacrintts  asieria  may  be  taken  as  the  type  of 
its  order;  I  will  therefore  describe  it  briefly.  The 
animal  consists  of  two  well-marked  portions,  a  stem 
and  a  head.  The  stem,  which  is  often  from  40  to 
60    centimetres   in   length,    consists    of    a    series   of 

F  r  2 


Fig.  70.— rentacrinvs  asteria,  Linn^us.    One-fourth  the  natural  size. 


CHAP.  IX.]  THE  DEEP-SEA  FAUNA.  437 

flattened  calcareous  joints ;  it  may  be  snapped  over 
at  the  point  of  junction  between  any  two  of  these 
joints,  and  by  slipping  the  point  of  a  pen-knife  into 
the  next  suture  a  single  joint  may  be  removed  entire. 
The  joint  has  a  hole  in  the  centre,  through  which 
one  might  pass  a  fine  needle.  This  hole  forms  part 
of  a  canal  filled  during  life  with  a  gelatinous  nutri- 
ent matter  which  runs  through  the  whole  length 
of  the  stem,  branches  in  a  complicated  way  through 
the  plates  of  the  cup,  and  finally  passes  through 
the  axis  of  each  of  the  joints  of  the  arms,  and  of 
the  ultimate  pinnules  which  fringe  them.  On  the 
upper  and  low^er  surfaces  of  the  stem-joint  there 
is  a  very  graceful  and  characteristic  figure  of  five 
radiating  oval  leaf-like  spaces,  each  space  surrounded 
by  a  border  of  minute  alternate  ridges  and  grooves. 
The  ridges  of  tlie  upper  surface  of  a  joint  fit  into 
the  grooves  of  the  lower  surface  of  the  joint  above 
it ;  so  that,  though  from  being  made  up  of  man 
joints  the  stem  admits  of  a  certain  amount  of 
motion,  that  motion  is  very  limited. 

As  the  border  of  each  star-like  figure  exactly 
fits  the  border  of  the  star  above  and  below,  the  five 
leaflets  within  the  border  are  likewise  placed  directly 
one  above  the  other.  Within  these  leaflets  the 
limy  matter  which  makes  up  the  great  bulk  of  the 
joint  is  more  loosely  arranged  than  it  is  outside,  and 
five  oval  bands  of  strong  fibres  pass  in  the  inter- 
spaces right  through  the  joints,  from  joint  to  joint, 
from  one  end  of  the  stem  to  the  other.  These 
fibrous  bands  give  the  column  great  strength.  It 
is  by  no  means  easily  broken  even  when  dead  and 
dry.     They  also,  by  their  elasticity,  admit  a  certain 


43 S  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

amount  of  passive  motion.  There  are  no  muscles 
between  the  joints  of  the  stem,  so  that  the  animal 
does  not  appear  to  be  able  to  move  its  stalk  at 
will.  It  is  probably  only  gently  w^aved  by  the  tides 
and  currents,  and  bv  the  movements  of  its  own  arms. 

In  Pentacrinus  asteria  about  every  seventeenth 
joint  of  the  lower  mature  part  of  the  stem,  is  a  little 
deeper  or  thicker  than  the  others,  and  bears  a  whorl 
of  five  long  tendrils  or  cirri.  The  stem  is,  even 
near  the  base,  slightly  pentagonal  in  section,  and 
it  becomes  more  markedly  so  towards  the  head. 
The  cirri  start  from  shallow  grooves  between  the 
projecting  angles  of  the  pentagon,  so  that  they  are 
ranged  in  five  straight  rows  up  and  down  the  stem. 
The  cirri  are  made  up  of  about  thirty-six  to  thirty- 
seven  short  joints  ;  they  start  straight  out  from  the 
stem  rigid  and  stiff,  but  at  the  end  they  usually 
curve  downwards,  and  the  last  joint  is  sharp  and 
clawlike.  These  tendrils  have  no  true  muscles : 
they  have,  however,  some  power  of  contracting  round 
resisting  objects  which  they  touch,  and  there  are 
often  star-fishes  and  other  sea  animals  entangled 
among  them.  The  specimen  figured  has  thus  be- 
come the  temporary  abode  of  a  very  elegant  species 
of  Asteroporpa. 

Near  the  head  the  cirri  become  shorter  and 
smaller,  and  their  whorls  closer.  The  reason  of 
this  is  that  the  stem  grows  immediately  below  the 
head,  and  the  cirrus-bearing  joints  are  formed  in 
this  position,  the  intermediate  joints  being  produced 
afterwards  balow  and  above  each  cirrated  joint, — 
which  they  gradually  separate  from  the  one  on  either 
side  of  it,  till  the  number  of  seventeen  or  eighteen 


CHAP.  IX.]  THE  DEEP-SEA  FAUNA.  439 

intermediate  joints  is  complete.  At  the  top  of  the 
stem  five  little  calcareous  lumps  like  buttons  stand 
out  from  the  projecting  ridges,  and  upon  these  and 
upon  the  upper  part  of  the  stem  the  cup  which 
holds  the  viscera  of  the  animal  is  placed.  These 
buttons  are  of  but  little  moment  in  this  form,  but 
they  represent  joints  which  are  often  developed  into 
large,  highly-ornamented  plates  in  the  various  tribes 
of  its  fossil  ancestors.  They  are  called  the  '  basal ' 
plates  of  the  cup.  Next,  in  an  upper  tier,  alternating 
with  the  last,  we  have  a  row  of  five  oblong  plates 
opposite  the  grooves  of  the  stem,  and  all  cemented 
into  a  ring.  These  plates  are  separate  when  the 
animal  is  young ;  they  are  called  the  '  first  radial ' 
plates.  They  are  the  first  of  long  chains  of  joints 
which  are  continued  to  the  ends  of  the  arms.  Imme- 
diately above  these  plates,  and  resting  upon  them, 
there  is  a  second  row  of  plates  nearly  of  the  same 
size  and  shape,  only  they  remain  separate  from  one 
another,  never  uniting  into  a  ring.  These  are  the 
'  second  radials,'  and  immediately  upon  these  rest 
a  third  series  of  five,  very  like  the  plates  of  the 
other  two  rows,  only  their  upper  surfaces  rise  into 
a  cross  ridge  in  the  centre,  and  they  have  the 
two  sides  bevelled  off  like  the  eaves  of  a  gable,  to 
admit  of  two  joints  being  seated  upon  each  of  them 
instead  of  one.  This  last  ring  of  joints  are  the 
'  radial  axillaries,'  and  above  these  we  have  the  first 
bifurcation  of  the  arms.  These  three  rings  of 
radial  joints  form  the  true  cup.  In  the  modern 
species  they  are  very  small,  but  in  many  fossils 
they  acquire  a  large  size,  and  enclose,  frequently 
with   the   aid  of   various    rows   of   intermediate   or 


440  THE  DEPTHS  OF  TEE  SEA.  [chap.  ix. 

inter-radial  plates  and  a  row  of  basals,  a  large 
body-cavity.  The  two  upper  joints  of  each  ray 
are  separated  from  those  of  the  ray  next  it  by  a 
prolongation  downwards  of  the  plated  skin  which 
covers  the  upper  surface  or  '  disk '  of  the  body. 
Seated  upon  the  bevelled  sides  of  each  radial-axil- 
lary joint,  there  is  a  series  of  five  joints,  the  last 
of  the  five  bevelled  again  like  the  radial  axillaries 
for  the  insertion  of  two  joints.  These  five  joints 
form  the  first  series  of  *  brachials/  and  from  the 
base  of  this  series  the  arms  become  free. 

The  first  of  the  brachial  joints,  that  is  to  say, 
the  joint  immediately  above  the  radial  axillary,  is, 
as  it  w^ere,  split  in  two  by  a  peculiar  kind  of  joint, 
called,  by  Miiller,  a  '  syzygy.'  All  the  ordinary  joints 
of  the  arms  are  provided  with  muscles  producing 
various  motions,  and  binding  the  joints  firmly 
together.  The  syzygies  are  not  so  provided,  and 
the  arms  are  consequently  easily  snapped  across 
where  these  occur.  This  is  a  beautiful  provisicm  for 
the  safety  of  an  animal  which  has  so  wide  and 
complicated  a  crown  of  appendages.  If  one  of  the 
arms  get  entangled,  or  fall  into  the  jaws  or  claws  of 
an  enemy,  by  a  jerk  the  star-fish  can  at  once  get 
rid  of  the  embarrassed  arm ;  and  as  all  this  group 
have  a  wonderful  power  of  reproducing  lost  parts,  the 
arm  is  soon  restored. 

When  the  animal  is  dying,  it  generally  breaks  off 
its  arms  at  these  syzygies ;  so  that  almost  all  the 
specimens  which  have  been  brought  to  Europe  have 
arrived  with  the  arms  separate  from  the  body. 

About  six  arm-joints  or  so  above  the  first  on 
either  branch  there  is  a  second  brachial  accessorv  and 


CHAP.  IX.]  THE  DEEP-SEA  FJUNA.  441 

another  bifurcation,  and  seven  or  eight  joints  farther 
on  another,  and  so  on,  but  more  irregularly  the 
farther  from  the  centre,  till  each  of  the  five  primary 
rays  has  divided  into  from  twenty  to  thirty  ultimate 
branches,  producing  a  rich  crown  of  more  than  a 
hundred  arms.  The  upper  surface  of  each  arm-joint 
is  deeply  grooved,  the  lower  arched ;  and  from  one 
side  of  each,  alternately  on  either  side  of  the  arm, 
there  springs  a  series  of  flattened  ossicles.  These 
form  the  ultimate  branchlets,  or  *  pinnules,'  which 
fringe  the  arms  as  the  barbs  fringe  the  shaft  of  a 
feather.  Unfortunately,  most  of  the  examples  of 
Fentacrinus  asteria  hitherto  procured  have  had  the 
soft  parts  destroyed  and  the  disk  more  or  less  injured. 
One  specimen,  however,  in  my  possession  is  quite 
perfect.  The  body  is  covered  above  by  a  membrane 
closely  tesselated  with  irregularly-formed  flat  plates; 
this  membrane,  after  covering  the  disk,  dips  into 
the  spaces  between  the  series  of  radial  joints,  and 
with  the  joints  of  the  cup  completes  the  body-wall. 
The  mouth  is  a  rounded  opening  of  considerable  size 
in  the  centre  of  the  disk,  and  opens  into  a  stomach 
passing  into  a  short  curved  intestine  which  ends  in 
a  long  excretory  tube, — the  so-called  '  proboscis  '  of 
the  fossil  crinoids, — which  rises  from  the  surface  of 
the  disk  near  the  mouth.  Prom  the  mouth  five 
deep  grooves,  bordered  on  either  side  by  small  square 
plates,  run  out  to  the  edge  of  the  disk,  and  are  con- 
tinuous with  the  grooves  on  the  upper  surface  of  the 
arms  and  pinnules,  while  in  the  angles  between  them 
five  thickened  masses  of  the  mailing  of  the  disk 
surround  the  mouth  like  valves.  These  were  at 
first  supposed  to  answer  the  purpose  of  teeth.     The 


442  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

crinoids,  however,  are  not  predatory  animals.  Their 
nutrition  is  effected  in  a  very  gentle  manner.  The 
grooves  of  the  pinnules  and  arms  are  richly  ciliated. 
The  crinoid  expands  its  arms  like  the  petals  of  a  full- 
blown flower,  and  a  current  of  sea-water  bearing 
organic  matter  in  solution  and  suspension  is  carried 
by  the  cilia  along  the  brachial  and  radial  grooves 
to  the  mouth.  In  the  stomach  and  intestine  the 
water  is  exhausted  of  assimilable  matter,  and  the 
length  and  direction  of  the  excretory  proboscis  pre- 
vent the  exhausted  water  from  returning  at  once  into 
the  ciliated  passages. 

The  other  West  Indian  Fentacrinus — P.  Miilleri — 
seems  to  be  more  common  off  the  Danish  Islands 
than  P.  asteria.  The  animal  is  more  delicate  in 
form.  The  stem  attains  nearly  the  same  height, 
but  is  more  slender.  The  rings  of  cirri  occur  about 
every  twelfth  joint,  and  at  each  whorl  two  stem- 
joints  are  modified.  The  upper  joint  bears  the  facet 
for  the  insertion  of  the  cirrus,  and  the  second  is 
grooved  to  receive  its  thick  basal  portion,  which 
bends  downwards  for  a  little  way  closely  adpressed 
to  the  stem,  before  becoming  free.  The  syzygy  is 
between  the  two  modified  joints,  and  in  all  the  com- 
plete specimens  which  I  have  seen  the  stem  is  broken 
through  at  one  of  these  stem  syzygies,  and  the  ter- 
minal stem-joint  is  w^orn  and  absorbed,  showing 
that  the  animal  must  have  been  for  long  free  from 
any  attachment  to  the  ground. 

On  the  21st  of  July,  1870,  Mr.  Gwyn  Jeffreys, 
dredging  from  the  '  Porcupine '  at  a  depth  of  1,095 
fathoms,  lat.  39°  42'  N.,  long.  9°  43'  W.,  with  a 
bottom  temperature  of  4°*3  C.  and  a  bottom  of  soft 


Fio.  71. — PentazrUms  wyvilh-thomioni,  Jeffrevs. 


Nitural  siz;.    (No.  17,  1870.) 


444  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

mud,  took  about  twenty  specimens  of  a  handsome 
Pentacrinus  involved  in  the  '  hempen  tangles ; '  and 
this  splendid  addition  to  the  fauna  of  the  European 
seas  my  friend  has  done  me  the  honour  to  associate 
Avith  my  name. 

Fentacrinus  wyville4homsoni,  Jeffreys   (Eig.  71), 
is  intermediate  in  some  of  its  characters  between  P. 
asteria  and  P.  miilleri;  it  approaches  the  latter  species, 
however,  the  more  nearly.    In  a  mature  specimen  the 
stem  is  about  120  mm.  in  length,  and  consists  of  five 
or  six  internodes.    The  whorls  of  cirri  towards  the 
lower  part  of  the  stem  are  40  mm.  apart,  and  the  in- 
ternodes contain  from  thirty  to  thirty-five  joints.    The 
cirri  are  rather  short  and  stand  straight  out  from  the 
nodal  joint,  or  curve  sharply  downwards,  as  in  P. 
asteria.     The  nodal  joint  is  single,  and  the  syzygy 
separates  it  from  the  joint  immediately  beneath  it, 
which  does  not  differ  materially  from  the  ordinary 
internodal   stem-joint.      All    the    stems    of   mature 
examples  of  this  species  end  uniformly  in  a  nodal 
joint,  surrounded  with  its  whorl  of  cirri,  which  curve 
downwards  into  a  kind  of  grappling  root.     The  lower 
surface  of  the  terminal  joint  is  in  all  smoothed  and 
rounded,  evidently  by  absorption,  showing  that  the 
animal  had  for   long   been  free.     This   character  I 
have  remarked  as  occurring  in  some  specimens  of 
P.  miilleri,     I  have  no  doiibt  that  it  is  constant  in 
the  present  species,  and  that  the  animal  lives  loosely 
rooted  in  the  soft  mud,  and  can  change  its  place  at 
pleasure  by  swimming  with  its  pinnated  arms ;  that 
it  is  in  fact  intermediate   in   this    respect   between 
the   free  genus  Antedon  and  the  permanently  fixed 
crinoids. 


CHAP.  IX.]  THE  DEEP-SEA  FAVNA.  445 

A  young  specimen  of  P.  icyville-thomsoni  gives  the 
mDde  in  which  this  freedom  is  acquired.  The  total 
length  of  this  specimen  is  95  mm.,  of  whicli  the  head 
occupies  35  mm.  The  stem  is  broken  off  in  the 
middle  of  the  eighth  internode  from  the  head.  The 
lowest  complete  internode  consists  of  14  joints,  the 
next  of  18,  the  next  of  20,  and  the  next  of  26  joints. 
There  are  8  joints  in  the  cirri  of  the  lowest  whorl, 
10  in  those  of  the  second,  12  in  those  of  the  third, 
and  14  in  those  of  the  fourth.  This  is  the  reverse  of 
the  condition  in  adult  specimens,  in  all  of  which  the 
numbers  of  joints  in  the  internodes,  and  of  joints 
in  the  cirri,  decrease  regularly  from  below  upwards. 
The  broken  internode  in  the  young  example,  and 
the  three  internodes  above  it,  are  atrophied  and  un- 
developed, and  suddenly  at  the  third  node  from  the 
head  the  stem  increases  in  thickness,  and  looks  as 
if  it  were  fully  nourished.  There  can  be  no  doubt 
that  in  early  life  the  crinoid  is  attached,  and  that  it 
becomes  disengaged  by  the  withering  of  the  lower 
part  of  the  stem. 

The  structure  of  the  cup  is  the  same  as  in  P. 
asteria  and  P.  mulleri.  The  basals  appear  in  the 
form  of  shield- like  projections  crowning  the  salient 
angles  of  the  stem.  Alternating  with  these  we  have 
well-developed  first  radials,  forming  a  closed  ring 
and  articulating  to  free  second  radials  by  muscular 
joints.  The  second  radials  are  united  by  a  syzygy 
to  the  radial  axillaries,  which  as  usual  give  off  each 
two  first  brachials  from  their  bevelled  sides.  A 
second  brachial  is  united  by  syzygy  to  the  first, 
and  normally  this  second  brachial  is  an  axillary, 
and  gives  off  two  simple  arms ;   sometimes,  however. 


446  THE  DEPTHS  OF  THE  SEA.         ,  [chap.  ix. 

the  radial  axillary  originates  a  simple  arm  only  from 
one  or  both  of  its  sides,  thus  reducing  the  total 
number  of  the  arms ;  and  sometimes  one  of  the  four 
arms  given  off  from  the  brachial  axillaries  again 
divides,  in  which  case  the  total  number  of  arms  is 
increased.  The  structure  of  the  disk  is  much  the 
same  as  in  the  species  of  the  genus  previously  known. 

Two  other  fixed  crinoids  were  dredged  from  the  \ 
'  Porcupine,'  and  these  must  be  referred  to  the  Apio-  \ 
crinidae,  which  differ  from  all  other  sections  of  the  1 
order  in  the  structure  of  the  upper  part  of  the  stem.  \ 
At  a  certain  point,  considerably  below  the  crown  of  | 
arms,  the  joints  of  the  stem  widen  by  the  greater  j 
development  of  the  calcareous  ring,  the  central  • 
tube  only  increasing  very  slightly  in  width.  The  \ 
widening  of  the  stem  joints  increases  upwards  until  [ 
a  pear-shaped  body  is  produced,  usually  very  elegant  j 
in  form,  which,  looking  from  the  outside,  one  would  j 
take  for  the  calyx.  It  is,  however,  nothing  more  j 
than  a  symmetrical  thickening  of  the  stem,  and  the  j 
body-cavity  occupies  a  shallow  depression  in  the  top  I 
of  it  included  within  the  plates  of  the  cup— the  j 
basals  and  radials — which  are  thicker  and  more  \ 
solid  thyn  in  other  crinoids,  but  otherwise  normally  i 
arranged.  The  stem  is  usually  long  and  simple  \ 
until  near  the  base,  where  it  forms  some  means  of-j 
attachment,  either  as  in  the  celebrated  pear-encrinites  \ 
of  the  forest  marble,  a  complicated  arrangement  of  \ 
concentric  layers  of  calcareous  cement  which  fix  it  t 
firmly  to  some  foreign  body,  or,  as  in  the  chalk  | 
Bourgtietticrinus  and  in  the  recent  RJiizocrinus,  an  ' 
irres^ular  series  of  jointed  branching  cirri. 

Tje  Apiocrinidae  attained  their  maximum  during  ' 


CHAP.  IX.]  THE  DEEP-SEA  FAUNA.  447 

the  Jurassic  period,  when  they  were  represented  by 
many  fine  species  of  the  genera  ApiocriPMs  and 
Millericrinus.  The  chalk  genus  Bourguetticrinus 
shows  many  symptoms  of  degeneracy.  The  head 
is  small,  and  the  arms  are  small  and  short.  The 
arm-joints  are  so  minute  that  it  is  scarcely  possible 
to  make  lip  a  series  from  the  fragments  scattered 
through  the  chalk  in  the  neighbourhood  of  a  cluster 
of  heads.  The  stem,  on  the  other  hand,  is  dispro- 
portionately large  and  long,  and  one  is  led  to  suspect 
that  the  animal  w^as  nourished  chiefly  by  the  general 
surface  absorption  of  organic  matter,  and  that  the 
head  and  special  assimilative  organs  were  principally 
concerned  in  the  function  of  reproduction.  Rhizo- 
crinus  loffotensis,  M.  Sars  (Fig.  72),  was  discovered 
in  the  year  1864,  at  a  depth  of  about  300  fathoms, 
off  the  Loffoten  islands,  by  G.  O.  Sars,  a  son  of  the 
celebrated  Professor  of  Natural  History  in  the  Uni- 
versity of  Christiania  by  whom  it  was  described  in 
the  year  1868.  It  is  obviously  a  form  of  the  Apio- 
crinidse  still  more  degraded  than  Bourguetticrinus, 
which  it  closely  resembles.  The  stem  is  long  and 
of  considerable  thickness  in  proportion  to  the  size 
of  the  head.  The  joints  of  the  stem  are  individually 
long  and  dice-box  shaped,  and  between  the  joints 
spaces  are  left  on  either  side  of  the  stem  alternately, 
as  in  Bourguetticrinus  and  in  the  pentacrinoid  of 
Antedon,  for  the  insertion  of  fascicles  of  contractile 
fibres.  Towards  the  base  of  the  stem  branches 
spring  from  the  upper  part  of  the  joints  ;  and  these, 
each  composed  of  a  succession  of  gradually  diminish- 
ing joints,  divide  and  re- divide  into  a  bunch  of 
fibres,  which  frequently  expand  at  the  ends  into  thin 


448  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

calcareous  laminae,  clinging  to  small  pieces  of  shell, 
grains  of  sand — anything  which  may  improve  the 
anchorage  of  the  crinuid  in  the  soft  mud  which  is 
nearly  universal  at  great  depths. 

In   Rhizocrmus  the  basal  series  of  plates  of  the 
cup  are   not  distinguishable.     They  are   masked  in 
a  closed  ring  at  the  top  of  the  stem;  and  whether 
the  ring  be  composed  of  the  fused  basals  alone,  or 
of  an   upper  stem-joint  with   the   basals   within   it 
forming  a  *  rosette,'  as  in  the  calyx  of  Antedon,  is  -. 
a  question  which  can  only  be  solved  by  a  careful  i 
tracing  of  successive  stages   of  development.      The  ' 
first  radials  are  likewise  fused,  and  form  the  upper  i 
wider  portion  of  the  funnel-shaped  calyx.     The  first  \ 
radials  are  deeply  excavated  above  for  the  insertion  | 
of  the  muscles  and  ligaments  which  unite  them  to  ( 
the  second  radials  by  a  true   (or  moveable)  joint.  | 
One  of  the  most  remarkable  points   in    connection  j 
with  this  species  is,  that  the  first  radials — the  first  i 
joints   of   the   arm — are  variable  in   number,   some  | 
examples  having  four  rays,  some  five,  some  six,  and  I 
a  very  small  number  seven,  in   the  following  pro-  j 
portions.     Out  of  seventy-five  specimens   examined  I 
by  Sars,  there  were —  I 

arms.  I 


15 

with 

i 

43 

5> 

5 

15 

11 

6 

2 

n 

7 

This  variability  in  so  important  a  character,  par-  j 
ticularly  when  associated  with  so  great  a  preponr  j 
derance  in  bulk  of  the  vegetative  over  the  more ! 
specially  animal  parts  of  the  organism,  must  un-  i 
doubtedly  be  accepted  as  indicating  a  deterioration 


CHAP.  IX.]  TITE  DEEP  SEA  FAUN  J.  449 

from  tlie  symmetry  and  compactness   of  tlie  Apio- 
crinidji3  of  the  Jurassic  period. 

The  anchylosed  ring  of  first  radials  is  succeeded  hy 
a  tier  of  free  second  radials,  which  are  united  l)y  a 
strai^^ht  syzygial  suture  to  the  next  series — the  radial 
axillaries.  The  surface  of  the  funnel-shaped  dilatation 
of  the  stem,  headed  hy  the  ring  of  first  radials,  is 
smooth  and  uniform,  and  the  second  radials  and 
radial  axillaries  present  a  smooth,  regularly-arched 
outer  surface.  The  radial  axillaries  differ  from  the 
corresponding  joints  in  most  other  known  crinoids 
in  contracting  slightly  a  hove,  presenting  only  one 
articulating  facet,  and  giving  origin  to  a  single  arm. 
The  arms,  which  in  the  larger  specimens  are  from  10 
to  12  mm.  in  length,  consist  of  a  series  of  from  ahout 
twenty-eight  to  thirty-four  joints,  uniformly  trans- 
versely arched  externally,  and  deeply  grooved  within 
to  receive  the  soft  parts.  Each  alternate  joint  bears 
a  pinnule,  the  pinnules  alternating  on  either  side  of 
the  axis  of  the  arm,  and  the  joint  which  does  not 
I  bear  a  pinnule  is  united  to  the  pinnule-bearing  joint 
I  above  it  by  a  syzygy :  thus  joints  with  muscular 
'  connections  and  syzygies  alternate  throughout  the 
whole  length  of  the  arm. 

The  pinnules,  twelve  to  fourteen  in  number,  eon- 

,  sist  of  a  uniform  series  of  minute  joints,  united  by 

I  muscular  connections.     The  grooves  of  the  arms  and 

[  of  the  pinnules  are  bordered  by  a  double  series  of 

I  delicate  round  fenestrated  calcareous  plates,  which, 

when  the  animal  is  contracted  and  at  rest,  form  a 

.closely  imbricated  covering   to   the   nerve,  and  the 

radial  vessel  with  its  delicate  csecal  tentacles.     The 

mouth  is  placed  in  the  centre  of  the  disk,  and  radial 

G  G 


450  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

canals,  equal  in  number  to  the  number  of  arms,  pass 
across  the  disk,  and  are  continuous  with  the  arm- 
grooves.  The  mouth  is  surrounded  by  a  row  of 
flexible  cirri,  arranged  nearly  as  in  the  pentacrinoid 
of  Antedon,  and  is  provided  with  five  oval  calcareous 
valve-like  plates  occupying  the  interradial  angles, 
and  closing  over  the  mouth  at  will.  A  low  papilla 
in  one  of  the  interradial  spaces  indicates  the  position 
of  the  minute  excretory  orifice. 

Rhizocrinus  loffotensis  is  a  very  interesting  addition 
to  the  British  fauna.     We  met  with  it  in  the  Tseroe 
Channel  in  the  year  18G9 — three  examples,  greatly 
mutilated,  at  a  depth  of  530  fathoms,  with  a  bottom 
temperature  of  6°-4C.,   Station  12  (1868).     Several 
occurred  attached  to  the  beards  of  the  Soltenice,  off 
the  Butt  of  the  Lews,  and  specimens  of  considerable 
size  were  dredged  in  862   fathoms   off  Cape  Clear.  \ 
The  range  of  this  species  is  evidently  very  wide.     It  j 
has  been  dredged  by  G.  O.    Sars  off   the  north   of; 
Norway;  by  Count  Pourtales  in  the  Gulf- stream  off 
the  coast  of  Elorida ;  by  the  Naturalists  on   board ; 
the  '  Josephine,'  on  the  '  Josephine  Bank,'  near  the  \ 
entrance  of  the  Strait  of  Gibraltar ;  and  by  ourselves  ■ 
between   Shetland  and  Eseroe,  and  off  Ushant  and  J 
Cape  Clear.  \ 

The  genus  Bathycrinus  must  also  be  referred  to  thai 
Apiocrinidse,  since  the  lower  portion  of  the  head  con- 
sists of  a  gradually  expanding  funnel-shaped  piece,; 
which  seems  to  be  composed  of  coalesced  upper  stem-" 
joints.  ! 

The  stem  of  Bathycrinus  gracilis  (Fig.  73)  is  long  andj;' 
delicate  ;  in  one  example  of  a  stem  alone,  which  came; 
up  in  the  same  haul  with  the  one  nearly  perfect  speci- 


Fict.  72. —Rhizocrinits  loffotemis,  M.  Sars.    Once  and  a  half  the  natural  size.  (No.  43, 18()t).) 

G  G  2 


452  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

men  which  was  procured,  it  was  90  mm.  in  length. 
The  joints  are  dice-hox  shaped,  as  in  Rhizocrinus, 
long  and  delicate  towards  the  lower  part  of  the  stem, 
3*0  mm.  in  length  hy  0*5  in  width  in  the  centre 
of  the  joint,  the  ends  expanding  to  a  width  of 
10  mm.  As  in  Hhizocrimis,  the  joints  of  the  stem 
diminish  in  length  towards  the  head,  and  additions 
are  made  in  the  form  of  calcareous  lamina3  heneath 
the  coalesced  joints  Avhich  form  the  base  of  the  cup. 

The  first  radials  are  five  in  number.  They  are 
closely  apposed,  but  they  do  not  seem  to  be  fused 
as  in  Rhizocrimis,  since  the  sutures  show  quite  dis- 
tinctly. The  centre  of  each  of  these  first  radials  rises 
into  a  sharp  keel,  while  the  sides  are  slightly  de- 
pressed towards  the  suture,  which  gives  the  calyx  a 
fluted  appearance,  like  a  folded  filter-paper.  The 
second  radials  are  long,  and  free  from  one  another, 
joining  the  radial  axillaries  by  a  straight  syzygial 
union.  They  are  most  peculiar  in  form.  A  strong 
plate-like  keel  runs  down  the  centre  of  the  outer 
surfaces,  and  the  joint  is  deeply  excavated  on  either 
side,  rising  again  slightly  towards  the  edges.  The 
radial  axillary  shows  a  continuation  of  the  same  keel 
through  its  lower  half,  and  midway  up  the  joint  the 
keel  bifurcates,  leaving  a  very  characteristic  diamond- 
shaped  space  in  the  centre,  towards  the  top  of  the 
joint ;  two  facets  are  thus  formed  for  the  insertion  of 
two  first  radials ;  the  number  of  arms  is  therefore 
ten.  The  arms  are  perfectly  simple,  and  in  our  single 
specimen  consist  of  twelve  joints  each.  There  is  no 
trace  of  pinnules,  and  the  arms  resemble  in  character 
tlie  pinnules  of  Hhizocrinus.  The  first  brachial  is 
united  to  the  second  by  a  syzygial  joint,  but  after 


J 


Fio.  7?,.—Bathycrinus  gvucilis,  VVyville  Thomson. 


Twice  tlie  natural  size.    (No.  .'37.  18(JS».) 


454  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

that  the  syzygies  are  not  repeated,  so  that  there  is 
only  one  of  these  peculiar  junctions  in  each  arm. 
The  arm-grooves  are  bordered  by  circular  fenes- 
trated plates,  as  in  Uhizocrinus. 

Certain  marked  resemblances  in  the  structure  of 
the  stem,  in  the  structure  of  the  base  of  the  cup, 
and  in  the  form  and  arrangement  of  the  ultimate 
parts  of  the  arms,  evidently  associate  Bathyerinus 
with  Rhizocriniis,  but  the  differences  are  very  wide. 
Eive  free  keeled  and  sculptured  first  radials  replace 
the  uniform  smooth  ring  formed  by  these  j)lates 
in  Uhizocrinus.  The  radial  axillaries  give  off  each 
two  arms,  thus  recurring  to  the  more  usual  arrange- 
ment in  the  order,  and  the  alternate  syzygies  on 
the  arms,  which  form  so  remarkable  a  character  in 
Hhisoerimis,  are  absent. 

Only  one  nearly  complete  specimen  and  a  de- 
tached stem  of  this  very  remarkable  species  were 
met  with,  and  they  were  both  brought  up  from  the 
very  greatest  depth  which  has  as  yet  been  reached 
with  the  dredge,  2,435  fathoms,  at  the  mouth  of 
the  Bay  of  Biscay,  200  miles  south  of  Cape  Clear. 

It  would  seem,  in  our  present  state  of  knowledge, 
that  the  stalked  crinoids  are  members  of  the  deep- 
sea  fauna.  A  second  specimen  of  another  very 
remarkable  form,  Holopus  rangi^  D'Orbigny,  has 
lately  been  procured  from  deep  water  off  Barbadoes, 
and  that  species,  with  those  already  noted,  makes 
up  the  tale  of  living  forms  belonging  to  the  order 
which  are  known  at  the  present  time.  It  is  unwise 
to  prophesy;  but  when  we  consider  that  the  first 
few  scrapes  of  the  dredge  at  great  depths  have 
added    two    remarkable   new   species   to   the   living 


J 


:hap.  ix.J 


THE  DEEP-SEA  FAUNA. 


455 


representatives  of  this  group,  until  now  supposed 
to  be  on  the  verge  of  extinction,  and  that  all  the 
known  species  are  from  depths  beyond  the  limit 
of  ordinary  dredging,  we  are  led  to  anticipate  that 
crinoids  may  probably  form  rather  an  important 
element  in  the  abyssal  fauna. 


Fig.  74.—Archfistrrl}ifrons,  Wyville  Thomson.     Oral  a.spect.    Three-fonrths  the  natural  size 

(No.  57,  1869.) 


The  general  distribution  of  the  deep  sea  Asteridea 
has  already  been  referred  to.  Perhaps  the  most 
obvious  peculiarity  which  they  present  is  the  great 
preponderance  of  the  genera  Astrogonium,  Arcliaster, 
Astropecien,  and  their  allies.  Genera  belonging 
to   other    groups    do    not    apparently   become    less 


4o()  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

numerous,  for  species  of  Asteracanthion,  Crihrella, 
Asteriscus,  and  Ophidiaster  are  as  abundant  as  they 
are  at  lesser  depths ;  but  as  we  go  down  new  species 
with  tesselated  mailing  on  the  disk  and  massive 
marginal  plates  seem  to  be  perpetually  added.  In 
our  own  seas  some  few  very  characteristic  forms, 
such  as  Astrogonium  phrygiamnn  and  Archaster 
andromecla  and  parellii,  are  on  the  verge  of  the  deep 
water,  and  are  now  and  then  taken  at  the  outer 
limit  of  shore  dredging,  or  on  fishing-lines  ;  while  in 
the  deep  water  all  along  the  north  and  west  of  Scot- 
land Ash^ogonium  granulare,  Archaster  tenuispmus, 
and  Astropecten  arcticiis  abound,  and  the  dredge 
is  enriclied  from  time  to  time  with  examples  of  such 
forms  as  Archaster  hifrons  (Fig.  74),  A.  vexillifer,  and 
Astrogonium  tonglmanum,  MoBius.  Many  additions 
have  been  made  to  the  singular  little  group  of  which 
J^ter aster  may  be  taken  as  a  type,  but  I  am  inclined 

to  think  that  these  are  to 
be  referred  along  with  most 
of  the  characteristic  Ophiu- 
ridans  rather  to  a  fauna  in- 
habiting median  depths,  and 
coming  within  range  of  the 
naturalist's  dredge  on  the 
coast  of  Scandinavia,  than 
to   the   abyssal  fauna ;    and 

Via.  75  — Solaster    furclfcr,    Von    Dubkn  «^ 

(Jil^srSg.r''^'''^*''*"  '''^"^'"■^' ''''■   the  same  may  be  said  of  a 

few  other  forms,  such  as 
Solaster  furcifer  (Fig.  75),  and  Pedicellaster  typicus 
which,  although  beyond  the  200-fathom  line  on  the 
coast  of  Britain,  do  not  appear  to  have  a  great 
range  of  depth. 


CHAP.  IX.]  THE  DEEP-SEA  FAUNA.  4.") 7 

TA\enty-six  Ecliinideans  were  observed  during  the 
'  Lightning  '  and  '  Porcupine  '  cruises  off  the  coasts 
of  Britain  and  Portugal  at  depths  ranging  from  100 
to  2.435  fathoms,  at  which  latter  depth  the  group 
was  represented  by  a  small  variety  of  Echmiis  vor- 
reyiciis,  and  a  young  example  of  J3rissopsis  lyrifira. 

Among  the  Cidarida^,  Cidaris  pcqnllata,  Leske, 
occurs  in  enormous  numbers  over  hard  ground,  at 
depths  from  100  to  400  fathoms.  This  species  has 
a  very  wide  range,  inhabiting  an  apparently  un- 
broken belt  from  the  North  Cape  to  the  Strait  of 
Gibraltar,  and  then  passing  into  the  Mediterranean. 
This  is  a  variable  form,  within  narrow  limits  of 
variation.  The  southern  specimens  gradually  pass 
into  the  form, — it  can  scarcely  be  called  a  variety, — 
which  is  the  type  of  Lamarck's  species,  C.  hystrix. 
Cidaris  affinis,  Philippi,  is  very  common  in  the 
Mediterranean,  especially  along  the  African  coast. 
I  think  this  pretty  little  form  must  for  the 
present  be  considered  distinct.  The  body  spines 
are  bright  scarlet,  and  the  long  spines,  in  marked 
specimens,  are  brown  banded  with  red  or  rose,  so 
that  it  is  a  singularly  pretty  object. 

The  genus  Forocidaris  and  the  three  species  of  the 
family  Echinothuridse,  and  their  interesting  relations 
to  fossil  forms,  have  already  been  considered ;  but 
even  these  are  scarcely  more  suggestive  of  early 
times  than  two  geaera  of  irregular  urchins,  one 
dredged  off  the  coast  of  Scotland,  and  the  other  at 
the  mouth  of  the  English  Channel. 

The  first  of  these  is  Fourtalesia,  one  species  of 
which,  P.  jeffreysi,  has  already  been  figured  and 
described  (p.  108),     According  to  the  classification  of 


458  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

Desor,  which  makes  the  disjunct  arrangement  of  the 
ambulacra  at  the  apex  the  test  character  of  the 
Djsasteridae,  this  genus  should  be  referred  to  that 
group,  for  the  apical  disk  is  truly  decomposed  as  in 
Dysaster  and  Collyrites,  and  not  merely  drawn  out 
as  in  Ananchytes.  From  the  arrangement  and  form 
of  the  pore  areas,  however,  and  the  general  appear- 
ance and  habit  of  the  animal,  I  am  inclined  to  think 
with  Alexander  Agassiz,  that  its  affinities  are  more 
with  such  forms  as  Infulaster.  Fourtalesia  must  be 
aberrant  in  whatever  group  it  may  be  placed. 

The  other  genus  Neolampas,  A.  Ag.,  associates  itself 
with  the  Cassidulidse  in  virtue  of  the  nearly  central 
pentagonal  mouth  with  a  tolerably  distinct  flocelle, 
the  anal  opening  at  the  bottom  of  a  deep  posterior 
groove  excavated  in  a  projecting  rostellum,  the  nar- 
row ambulacral  areas,  and  the  small  compact  group 
of  apical  plates ;  but  it  differs  from  all  known  genera 
of  the  family,  living  or  extinct,  in  having  no  trace  of 
a  petaloid  arrangement  of  the  ambulacra,  which  are 
reduced  on  the  apical  surface  of  the  test  to  a  single 
pore  passing  through  each  ambulacral  plate,  and 
thus  forming  a  double  row  of  alternating  simple 
pores  for  each  ambulacral  area.  I  think  I  am  right 
in  identifying  a  single  specimen,  nearly  20  mm.  in 
length,  which  we  dredged  in  800  fathoms  water  at 
the  mouth  of  the  Channel,  with  the  species  dredged 
by  Count  Pourtales  at  depths  from  100  to  150 
fathoms,  in  the  Strait  of  Florida,  and  described  by 
Alexander  Agassiz  under  the  name  of  Neolampas 
rostellatus. 

Of  the  twenty- six  Echinoderms  dredged  from  the 
'  Porcupine,'  six — Echinus  flemingii,  Echinus  esculen- 


CHAP.  IX.]  THE  DEEP-SEA  FAUNA.  459 

tus,  PsammecJiimis  miliaris,  Echinocyamus  angulatus^ 
Amphidetus  cordatus,  and  Spatangiis  purpureus — may- 
be  regarded  as  denizens  of  moderate  depths  in  the 
'  Celtic  province/  recent  observations  having  merely 
shown  that  they  have  a  somewhat  greater  range  in 
depth  than  was  previously  supposed.      Probably  Spa- 
tmigus  raschi  may  be  an  essentially  deep-water  form 
having  its  head-quarters  in  the  same  region.     Seven 
species  —  CidmHs  papillata,  Hclimus  elegans,  JE.  nor- 
vegicus,  E.  rarispina,  E.  microstoma,  Brissopsis  lyri- 
fera,  and  Tripylus  fragilis — are  members  of  a  fauna 
of  intermediate  depth  ;  and  all,  with  the  doubtful  ex- 
ample of  Echinus  microstoma,  have  been  observed  in 
comparatively  shallow  water  off  the  coasts  of  Scan- 
dinavia.    Pive  species — Cidaris  affinis,  EcJiinus  melo, 
Toxop7ieustes     hrevispinosus,    Fsammechinus     micro- 
tuberculatus,  and  Schizaster  canaliferus — are   recog- 
nized members  of  the  Lusitanian  and  Mediterranean 
faun^  ;    and    seven — Borocidaris  purpurata,   Plior- 
mosoma    placenta,    Calveria   hystrix,    C.  fenestrata, 
Neolampas  rostellatus,  Fourtalesia  jeffreysi,  and  P. 
phiale — are  forms  which  have  been  for  the  first  time 
brought  to  light  during  the  late  deep-sea  dredging 
operations,  whether  on  this  or  on  the  other  side  of 
the  Atlantic.      There  seems  little   doubt  that  these 
must  be  referred  to  the  abyssal  fauna,  upon  whose 
confines  we   are   now   only   beginning  to   encroach. 
Three  of  the  most  remarkable  generic  forms — Cat- 
veria,  Neolampas,  and  Tourtalesia — have  been  found 
by  Alexander  Agassiz  among  the  results  of  the  dee}) 
dredging  operations  of  Count  Pourtales  in  the  Strait 
of  Plorida,  showing  a  wide  lateral  distribution,  while 
even   a    deeper   interest    attaches   to   the    fact   that 


4G0  THE  DEPTHS  OF  THE  SEJ.  [chap.  ix. 

Avliiie  one  family  type,  tlie  Eckmoilmridce,  has  been 
hitherto  only  known  in  a  fossil  state,  the  entire 
group  find  nearer  allies  in  the  extinct  faunae  of  the 
chalk  or  of  the  earlier  tertiaries  than  in  that  of 
the  present  period. 

As  I  have  already  said,  the  mollusca  procured 
during  the  three  years'  dredging  are  in  the  hands 
of  Mr.  Gwyn  Jeffreys  for  identification  and  descrip- 
tion. Erom  the  large  number  of  new  species,  and 
from  the  complicated  relations  which  many  of  the 
forms  from  deep  water  bear  to  species  now  widely 
separated  from  them  in  space,  or  belonging  to  past 
geological  periods,  the  task  will  be  a  difficult  one, 
and  we  cannot  expect  its  completion  for  some  time 
to  come.  In  the  meanwhile,  Mr.  Gwyn  Jeffreys 
has  published  several  preliminary  sketches  which 
are  full  of  promise  that  his  complete  results  will 
be  of  the  highest  interest. 

Mr.  Gwyn  Jeffreys  believes  that  the  deep-water 
mollusca  which  were  dred<>ed  throuo'hout  the  whole  of 
the  area  examined  from  the  Peeroe  Islands  to  the  coast 
of  Spain,  are  almost  all  of  northern  origin.  Most  of 
the  species  which  have  been  already  described  were 
previously  known  from  the  Scandinavian  seas,  and 
many  of  the  undescribed  species  belong  to  northern 
genera.  He  points  out  that  the  moUuscan  fauna 
of  the  Arctic  Sea  is  as  yet  almost  unknown  ;  but  he 
reasons  from  the  large  collections  made  at  Spitz- 
bergen  by  Professor  Torell,  and  from  the  fact  that 
fragments  of  mollusca  have  been  brought  up  in 
many  deep-sea  soundings  within  the  Arctic  circle, 
that  the  fauna  is  probably  varied  and  rich.  He 
instances  soundings  taken  in  1868  by  the  Swedish 


CHAP.  IX. J  THE  DEEP-SEA  FAUNA.  4(ji 

Arctic  Expedition,  which  reached  2,600  fathoms, 
when  a  Cmna  and  a  frai^ment  of  an  Astarie  came  up 
in  the  '  Bulldog  '  machine.  He  adds,  "  It  is  evident 
that  the  majority,  if  not  the  whole  of  our  submarine 
(as  contradistinguished  from  littoral  or  phytopha- 
gous), mollusca  originated  in  the  iXorth,  whence  they 
have  in  the  course  of  time  been  transported  south- 
wards bv  the  ffreat  Arctic  currents.  Manv  of  them 
appear  to  have  found  their  way  into  the  Mediterra- 
nean, or  to  have  k^ft  their  remains  in  the  tertiary  or 
quaternary  formations  of  the  south  of  Italy  ;  some 
have  even  migrated  into  the  Gulf  of  Mexico." 

I  have  great  hesitation  in  questioning  any  of  the 
conclusions  of  my  friend  Mr.  Gwyn  Jeffreys  on  a 
subject  in  which  he  is  so  excellent  an  authority, 
but  I  confess  I  do  not  quite  see  the  cogency  of  his 
reasoning  on  this  point.  It  would  seem  rather  that 
the  last  change  in  the  mollusca n  fauna  of  the  British 
area,  at  moderate  depths,  consisted  in  the  retirement 
of  northern  species  at  the  close  of  the  glacial  period 
and  the  immigration  of  southern  forms.  The  qua- 
ternary beds  of  the  Clyde  district  contain  a  rich 
assemblage  of  mollusca ;  those  of  the  neighbourhood 
of  llothesay  especially  representing  the  deeper  part 
of  the  Laminarian  and  the  Coralline  zone.  The 
broad  characteristic  of  the  fauna  of  this  bed  is 
that  many  of  the  most  numerous  species — for 
example,  Pecten  islandicus,  Tell'ma  calcarea,  and 
Natica  clausa — are  now  extinct  in  the  seas  of 
Britain,  but  are  still  met  with  in  abundance  in  the 
seas  of  Scandinavia  and  Labrador ;  w^hile  many  forms 
now  extremely  common  in  the  British  seas  and 
having   a   southern   extension    are    entirely   absent. 


462  THE  DEPTHS  OF  THE  SEA.  [chap.  ix. 

We  found  some  of  the  glacial  shells  of  the  Clyde 
beds  living  on  the  northern  outskirts  of  our  region, 
— Tellina  ccilcarea,  for  instance,  was  very  common 
in  some  of  the  Pjords  in  Eseroe.  It  seems  evident 
that  this  fauna  quietly  retreated  northwards  in  the 
face  of  slowly'  altering  circumstances.  Such  an 
instance  of  change  of  fauna,  which  we  are  able  in 
a  great  degree  to  trace  step  by  step,  has  an  interest- 
ing bearing  upon  the  great  question  of  the  contem- 
poraneity of  beds  containing  generally  the  same 
fauna  at  distant  localities.  We  can  well  imagine 
that  a  block  of  perfectly  recent  silt  might  be  brought 
from  a  locality  on  the  verge  of  the  Arctic  circle, 
imbedding  precisely  the  same  species  of  moUusca 
as  those  contained  in  a  block  of  the  Clyde  glacial 
clay,  and  the  mineral  character  of  the  matrix  in 
the  two  cases  might  correspond  most  closely ;  apply- 
ing the  ordinary  geological  rule,  those  two  blocks 
agreeing  in  their  palseontological  characters  ought 
to  be  contemporaneous, — but  we  know  that  while 
the  northern  silt  belongs  to  the  present  period,  the 
British  glacial  clays  are  overlain  by  a  deep  series 
of  modern  deposits,  representing  the  lapse  of  a 
period  of  time  considerable  even  in  a  geological 
sense,  and  containing  a  fauna  of  a  very  different 
character.  This  is  no  doubt  a  comparatively  trifling 
case,  involving  beds  of  no  great  depth  or  import- 
ance, but  it  is  a  case  in  which  two  beds  correspond 
palaeontologically,  and  yet  we  hnoic  that  they  are 
not  contemporaneous  from  one  of  them  being  overlain 
by  a  considerable  thickness  of  newer  strata,  while  the 
other  is  now  forming,  and  thus  furnishes  a  date,  a 
rare  and  valuable  thing  in  geology.  i 

i 


CHAP.  IX.]  THE  DEEP-SEA  FAUNA.  463 

I  have  already  pointed  out  that  in  reasoning  upon 
the  ground  of  identity  of  deep-sea  forms  with  species 
hitherto  found  in  Scandinavia,  we  must  remember 
that  the  conditions  of  temperature  of  our  southern 
seas  at  great  depths — the  conditions  which  appear  to 
have  the  greatest  influence  upon  the  distribution  of 
species — correspond  very  closely  with  those  of  much 
shallower  water  in  the  Scandinavian  seas ;  and  that 
consequently  the  corresponding  fauna  in  the  northern 
regions  was  much  earlier,  and  is  still  much  better 
known.  Mr.  Gwyn  Jeffreys  lays  great  stress  upon 
the  greater  numbers  and  the  greater  development 
in  size  and  in  prominent  characters  of  sculpture  and 
other  ornament,  of  the  Arctic  examples  of  species 
common  to  our  deep  water.  This  is  no  doubt  often 
the  case,  but  we  must  admit  that  in  many  groups, 
and  particularly  among  the  moUusca,  there  is  a 
tendency  to  dwarfing  in  deep  water,  and  I  should 
think  it  very  possible  that  a  species  may  attain 
a  greater  size  and  development  in  that  region  where 
its  zone  of  special  temperature  conditions  comes 
nearest  the  surface, — most  under  the  influence  of 
air  and  light. 

Many  of  the  mollusca  from  the  deep  water  have 
hitherto  been  found  only  in  the  northern  portions  of 
the  area  examined,  and  are  generally  allied  to  northern 
forms.  As  examples  of  this  group  I  may  mention 
two  interesting  additions  to  the  already  famous  Shet- 
land fauna,  Bticcinopsis  striata,  Jeffreys  (Eig.  76), 
a  form  somewhat  allied  to  Buccinopsis  dalei,  which 
has  long  been  one  of  the  prizes  of  the  Shetland  seas, 
and  Latirus  albus,  Jeffreys  (Eig.  77),  known  also 
from  the  coast  of  Norway.     CeritUum  granosum,  S. 


4(U  THI^  DEPTHS  OF  THE  SEA.  [chap.  ix. 

V.  Wood,  also  common  to  Norway  and  Shetland, 
is  found  fossil  in  the  coralline  and  red  crag,  and 
Fns'iis  sarsi,  Jeffreys,  common  to  Shetland  and 
Tsorvvay,  is  found  fossil  at   Eridlino'ton. 

Several  species  have  hitherto  been  known  only 
from  the  soutli,  and  Mr.  Jeffreys  finds  a  difficulty 
in  accounting  for  their  presence.  Thus,  Tellina  com- 
pressa,  BROCcni,  is  known  from  the  Canary  Islands 
and  the  Mediterranean,  and  is  fossil  in  the  ncAver 
Italian  tertiaries.     Feriicordia  acuticostata,  Philippi, 


Fig.  76.—Buccivopsis  striata,  Jeffkeyb.  Fig.  77. — LutirnsaVnts,  Jeffreys. 

Fici'oe  Channel.  Twice  tlie  natural  size.     Finnje 

Channel. 


I  have  already  referred  to  as  being  found  on  the 
coasts  of  Portugal  and  of  Japan.  It  is  a  common 
fossil  in  the  coralline  crag  of  Calabria.  The  mol- 
lusca  Avhich  are  of  the  most  special  interest,  how- 
ever, are  those  which  we  must  refer  to  the  abyssal 
fauna.  About  this  group  we  know  as  yet  very 
little.  Like  the  Echinoderms,  they  seem  to  be  special, 
and  to  have  a  wide  lateral  extension.  Pleuronectla 
lucid  a,  Jeffreys  (Pig.  78),  a  pretty  little  clam  be- 
longing to  tlie  Pecten  plevro7iectes  set,  is  figured 
both  from  the  Nortli  Atlantic  and  from  the  Gulf  of 


CHAP.    IX.] 


THE  DEEP-SEA  FAUNA. 


4G5 


Mexico.  The  abyssal  moUusea  are  by  no  means  de- 
void of  colour,  though,  as  a  rule,  they  are  paler  than 
those  from  shallow  water.  Dacrydium  vitreum — 
a  curious  little  mytiloid  shell-fish  which  makes  and 
inhabits  a  delicate  flask-shaped  tube  of  foraminifera, 


Fig.  7S.—Plf.uronectia  lucida,  Jeffreys.    Twice  the  natural  size,   a,  frointlie  Eastern  Atlantic  ; 
h,  from  the  Gulf  of  Mexioo. 

sponge  spicules,  coccoliths,  and  other  foreign  bodies, 
cemented  together  by  organic  matter  and  lined  by  a 
delicate  membrane — is  of  a  fine  reddish  brown  colour 
dashed   with   green,  from    2,435   fathoms;    and   the 


Fig.  79.  —Pecten  hosl-ynsi,  Forbes.    Twice  the  natural  size. 

animals  of  one  or  two  species  of  Lima  from  extreme 
depths  are  of  the  usual  vivid  orange  scarlet.  Neither 
are  the  abyssal  mollusca  universally  destitute  of  eyes. 
A  new  species  of  Fleurotoma  from  2,090  fathoms  had 
a  pair  of  well-developed  eyes  on  short  footstalks  ;  and 

H  II 


4G6 


THE  DEPTHS  OF  THE  SEA. 


[chap.   IX. 


a  Fasus  from  1,207  fathoms  was  similarly  provided. 
The  presence  of  organs  of  sight  at  these  great  depths 
leaves  little  room  to  douht  that  light  must  reach  even 
these  abysses  from  some  source.  From  many  con- 
siderations it  can  scarcely  be  sun-light.  I  have 
already  thrown  out  the  suggestion  that  the  whole 
of  the  light  beyond  a  certain  depth  might  be  due 
to  phosphorescence,  which  is  certainly  very  general, 
particularly  among  the  larvae  and  young  of  deep- 
sea  animals ;  but  the  question  is  one  of  extreme 
interest  and  difficulty,  and  will  require  careful  in- 
vestigation. 


BORDO,  KUNO,    AND   KALSu,  FROM   THE   HAMLET  OF   VIDFBO. 


CHAPTER  X. 


THE  CONTINUITY  OF  THE  CHALK. 

I 

B'  Points  of  Resemblance  between  the  Atlantic  Ooze  and  the  White 

B^  -      Chalk. — Differences  between  them. — Composition  of  Chalk. — The 

^K        Doctrine  of  the  Continuity  of  the  Chalk. — Objections. — Arguments 

^»         in  favour  of  the  View  from  Physical  Geology  and  Geography. — 

Former  Distribution  of  Sea  and  Land. — Palseontological  Evidence. 

— Chalk-flints. — Modern   Sponges,  and  Ventriculites.— Corals. — 

Echinoderms. — Mollusca. — Opinions  of  Professor  Huxley  and  Mr. 

Prestwich. — The  Composition  of  Sea- water. — Presence  of  Organic 

Matter. — Analysis  of  the  contained  Gases. — Differences  of  Specific 

Gravity. — Conclusion. 

'       Appendix  A. — Summary  of  the  Results  of  the  Examination  of  Samples 

of  Sea-water  taken  at  the  Surface  and  at  various  Depths.      By 

"William  Lant  Carpenter,  B.A.,  B.Sc. 
Appendix  B. — Results  of  the  Analyses  of  Eight  Samples  of  Sea-water 

collected  during  the  Third  Cruise  of  the  *  Porcupine.'     By  Dr. 

Erankland,  F.R.S. 
Appendix  C. — Notes  on  Specimens  of  the  Bottom  collected  during 

the  First  Cruise  of  the  'Porcupine'  in  1869.     By  David  Forbes, 

F.R.S. 
Appendix  D. — Note  on  the  Carbonic  Acid  contained  in  Sea-water. 

By  John  Young  Buchanan,  M.A.,  Chemist  to  the  'Challenger' 

Expedition. 

Very  speedily  after  the  first  samples  of  the  bottom  of 
the  mid- Atlantic  had  been  brought  up  by  the  sound- 
ing-line,  and    submitted   to   chemical   analysis   and 

H  H  2 


468  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

to  microscopical  examination,  many  observers  were 
struck  with  the  great  similarity  between  its  composi- 
tion and  structure  and  that  of  the  ancient  chalk.     I 
have  already  described  the  general  character  and  the 
mode  of  origin  of  the  great  calcareous  deposit  which 
seems  to  occupy  the  greater  part  of  the  bed  of  the 
Atlantic.     If  we  take  a  piece  of  the  ordinary  soft 
white  chalk  of  the  south  of  England,  wash  it  down 
with    a   brush  in  water,    and  place  a   drop  of  the 
milky  product  on  the  slide  of  a  microscope,  we  find 
that  it  consists,  like  the  Atlantic  ooze,  of  a  large  pro- 
portion of  fine  amorphous  particles  of  lime,  with  here 
and  there  a  portion  of  a  Glohigerina  shell,  and  more 
rarely  one  of  these  shells  entire,  and  a  considerable 
proportion — in  some  examples  coming  up  to  nearly 
one-tenth  of  the  whole — of  '  coccoliths,'    which   are 
indistinguishable  from  those  of  the  ooze.     Altogether 
two  slides — one  of  washed  down  white   chalk,   and 
the  other  of  Atlantic  ooze — resemble  one  another  so 
clearly,  that  it  is  not  always  easy  for  even  an  accom- 
plished microscopist  to  distinguish  them.    The  nature 
of  chalk  can  also  be  well  shown,  as  has  been  done  by 
Ehrenberg  and  Sorby,  by  cutting  it  into  thin  dia- 
phanous slices,  when  the  mode  of  aggregation  of  the 
different  materials  can  be  readily  demonstrated. 

But  while  successive  observers  have  brought  out 
more  and  more  clearly  those  resemblances, — suffi- 
ciently striking  to  place  it  beyond  a  doubt  that  the 
chalk  of  the  cretaceous  period  and  the  chalk-mud  of 
the  modern  Atlantic  are  substantially  the  same, — a 
more  careful  investigation  shows  that  there  are  very 
important  differences  between  them.  The  white  chalk 
is  very  homogeneous,  more  so  perhaps  than  any  other 


CHAP.  X.J  CONTINUITY  OF  THE  CHALK.  469 

sedimentary  rock,  and  may  be  said  to  be  almost  pure 
carbonate  of  lime.  I  quote  an  analysis  of  the  white 
chalk  of  Shoreham  (Sussex),  by  Mr.  David  Eorbes.^ 

Calcium  carbonate 98-40 

Magnesium  carbonate 0*08 

Insoluble  rock  (ie6?'i6' 1*10 

Alumina  and  loss 0*42 

100-00 

Even  the  grey  chalk  of  Eolkestone  contains  a  very 
large  proportion  of  carbonate  of  lime,  the  other  sub- 
stances existing  merely  as  impurities  which  can 
scarcely  be  said  to  enter  into  the  composition  of  the 
rock.  The  following  is  an  analysis  by  Mr.  Eorbes  of 
the  base  of  the  Eolkestone  grey  chalk  : — 

Calcium  carbonate 94-09 

Magnesium  carbonate 0'31 

Insoluble  rock  debris 3-61      , 

Phosphoric  acid 


( 


Alumina  and  loss 

Sodium  chloride 1-29 

Water 0*70 


10000 

The  most  remarkable  point  in  this  analysis  is  that 
while  white  chalk  is  almost  always  associated  with 
chert  and  flints,  the  chalk  itself  does  not  contain  a 
particle  of  silica. 

The  chalk-mud  of  the  Atlantic  on  the  other  hand 
contains  not  more  than  60  per  cent,  of  calcium  car- 
bonate, with  20  to  30  per  cent,  of  silica,  and  varying 
proportions  of  alumina,  magnesia,  and  oxide  of  iron. 
We  must  remember,  however,  that  in  the  English 

^  Quoted  in  Mr.  Prestwich's  Presidential  Address,  1871. 


470  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

cliffs  we  have  the  chalk  in  its  very  purest  form,  and 
that  in  various  parts  of  the  world  it  assumes  a  very 
different  character,  and  contains  carbonate  of  lime  in 
very  different  proportions.  Mr.  Prestwich  instances 
a  bed  28  to  30  feet  thick  of  the  white  chalk  (Terrain 
Senonien)  of  Touraine,  in  which  carbonate  of  lime  is 
entirely  absent. 

There  can  be  no  doubt  whatever  that  we  have 
forming  at  the  bottom  of  the  present  ocean,  a  vast 
sheet  of  rock  which  very  closely  resembles  chalk  ; 
and  there  can  be  as  little  doubt  that  the  old  chalk, 
the  cretaceous  formation  which  in  some  parts  of  Eng- 
land has  been  subjected  to  enormous  denudation,  and 
which  is  overlaid  by  the  beds  of  the  tertiary  series, 
was  produced  in  the  same  manner,  and  under  closely 
similar  circumstances ;  and  not  the  chalk  only,  but 
most  probably  all  the  great  limestone  formations.  In 
almost  all  of  these  the  remains  of  foraminifera  are 
abundant,  some  of  them  apparently  specifically  iden- 
tical with  living  forms ;  and  in  a  large  number  of 
limestones  of  all  ages  Dr.  GUmbel  has  detected  the 
characteristic  'coccoliths.' 

Long  before  commencing  the  present  investigation, 
certain  considerations  had  led  me  to  regard  it  as 
highly  probable  that  in  the  deeper  parts  of  the  At- 
lantic a  deposit,  differing  possibly  from  time  to  time 
in  composition  but  always  of  the  same  general  cha- 
racter, might  have  been  accumulating  continuously 
from  the  cretaceous  or  even  earlier  periods  to  the 
present  day.  This  view  I  suggested  in  my  first  letter 
to  Dr.  Carpenter  urging  the  exploration  of  the  sea- 
bed ;  and  from  the  first  it  has  had  the  cordial  support 
of  my  colleague,  whose  intimate  acquaintance  with 


CHAP.  X.]  CONTINUITY  OF  THE  CHALK.  471 

some  of  the  animal  groups  whose  remains  enter  most 
largely  into  the  chalk  hoth  old  and  new,  makes  his 
opinion  on  such  a  question  particularly  valuable. 

On  our  return  from  the  '  Lightning '  cruise,  during 
which  we  believed  that  our  speculation  had  received 
strong  confirmation,  we  used  the  expression, — perhaps 
somewhat  an  unfortunate  one  since  it  was  capable  of 
misconstruction, — that  we  might  be  regarded  in  a 
certain  sense  as  still  living  in  the  cretaceous  period. 
Several  very  eminent  geologists,  among  whom  were 
Sir  Roderick  Murchison  and  Sir  Charles  Lyell,  took 
exception  to  this  statement ;  but  it  seems  that  their 
censure  was  directed  less  against  the  opinion  than 
the  mode  in  which  it  was  expressed ;  and  I  think  I 
may  say  that  the  doctrine  of  the  continuity  of  the 
chalk,  in  the  sense  in  which  we  understood  it,  is  now 
very  generally  accepted. 

I  do  not  maintain  that  the  phrase  'we  are  still 
living  in  the  cretaceous  epoch,'  is  defensible  in  a 
strictly  scientific  sense,  chiefly  because  the  terms 
'  geological  epoch '  and  '  geological  period '  are 
thoroughly  indefinite.  We  speak  indifferently  of 
the  '  Silurian  period,'  and  the  '  Glacial  period,'  with- 
out consideration  of  their  totally  unequal  value ; 
and  of  the  'Tertiary  period,'  and  of  the  'Miocene 
period,'  although  the  one  includes  the  other.  The 
expression  is  intended  rather  in  a  popular  sense 
to  meet  what  was  certainly  until  very  lately  the 
general  popular  impression,  that  a  geological  period 
has,  in  the  region  where  it  has  been  studied  and 
defined,  something  like  a  beginning  and  an  end ; 
that  it  is  bounded  by  periods  of  change — elevation, 
denudation,  or  some  other  evidence  of  the  lapse  of 


472  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

unrecorded  time ;  and  that  it  would  be  inadmissible 
to  speak  of  two  portions  of  the  same  continuous 
deposit,  however  distant  the  times  of  their  deposition 
might  be,  and  however  distinct  their  imbedded 
faunae,  as  belonging  to  different  'Geological  periods/ 

It  was  certainly  in  this  sense  that  in  an  address  to 
a  popular  audience  in  April  1869  I  ventured  to  state 
my  belief  that  it  is  not  only  chalk  which  is  being 
formed  in  the  Atlantic,  ''but  the  chalk,  the  chalk  of 
the  cretaceous  period."  Sir  Charles  Lyell  says,  in 
summing  up  his  objections  to  this  view,^  "The 
reader  will  at  once  perceive  that  the  present  Atlantic, 
Pacific,  and  Indian  oceans,  are  geographical  terms 
which  must  be  wholly  without  meaning  when  applied 
to  the  eocene,  and  still  more  to  the  cretaceous  period, 
so  that  to  talk  of  the  chalk  having  been  uninter- 
ruptedly formed  in  the  Atlantic  is  as  inadmissible  in 
a  geographical  as  in  a  geological  sense."  I  confess 
I  do  not  see  the  geographical  difficulty;  the 
"Atlantic  ocean"  is,  undoubtedly,  a  geographical 
term,  but  the  depression  under  discussion  occupies 
the  area  at  present  expressed  by  that  term,  and  to 
use  it  seems  to  be  the  simplest  way  of  indicating  its 
position.  We  believe  that  the  balance  of  probability 
is  greatly  in  favour  of  the  chalk  having  been  unin- 
terruptedly forming  over  some  parts  of  the  area  in 
question,  and  our  belief  is  founded  upon  many  con- 
siderations, physical  and  palseontological. 

All  the  principal  axes  of  elevation  in  the  north  of 
Europe  and  in  North  America  have  a  date  long  an- 
terior to  the  deposition  of  the  tertiary,  or  even  of  the 

1  The  Student's  Elements  of  Geology.  By  Sir  Charles  Lyell,  Bart, 
F.R.S.     London,  1871.     P.  265. 


CHAP.  X.]  CONTINUITY  OF  THE  CHALK.  473 

newer  secondary  beds,  although  some  of  them,  such  as 
the  Alps  and  the  Pyrenees,  have  received  great  acces- 
sions to  their  height  in  later  times.  All  these  newer 
beds  have  therefore  been  deposited  with  a  certain  re- 
lation in  position  to  certain  main  features  of  contour 
which  are  maintained  to  the  present  day.  Many  oscil- 
lations have  doubtless  taken  place  since,  and  every 
spot  on  the  European  plateau  may  have  probably 
alternated  many  times  between  sea  and  land;  but  it  is 
difficult  to  show  that  these  oscillations  have  occurred 
in  the  north  of  Europe  to  a  greater  extent  than  from 
4,000  to  5,000  feet,  the  extreme  vertical  distance  be- 
tween the  base  of  the  tertiaries  and  the  highest  point 
at  which  tertiary  or  post-tertiary  shells  are  found  on 
the  slopes  and  ridges  of  mountains.  A  subsidence  of 
even  1,000  feet  would,  however,  be  sufficient  to  pro- 
duce over  most  of  the  northern  land  a  sea  100  fathoms 
deep,  deeper  than  the  German  Ocean ;  and  an  eleva- 
tion to  a  like  amount  would  connect  the  Shetland  and 
Orkney  Islands  and  Great  Britain  and  Ireland  with 
Denmark  and  Holland,  leaving  only  a  long  deep  Ejord 
separating  a  British  peninsula  from  Scandinavia. 
When  we  bear  in  mind  the  abundant  evidence 
which  we  have  that  these  minor  oscillations,  with  a 
maximum  range  of  4,000  to  5,000  feet,  have  occurred 
again  and  again  all  over  the  world  within  compara- 
tively recent  periods,  alternately  uniting  lands  and 
separating  them  by  shallow  seas,  the  position  of  the 
deep  water  remaining  throughout  the  same,  the  im- 
portance of  an  accurate  determination  of  the  depth  of 
intervening  sea  in  all  speculations  as  to  geographical 
distribution  and  the  origin  of  special  faunae  becomes 
most  apparent. 


474  TEE  DEPTHS  OF  THE  SEA.  [chap.  x. 

From  a  glance  at  the  map  (PI.  VIII.),  and  remem- 
bering that  nearly  the  same  arrangement  exists  in 
regard  to  the  newer  rocks  of  North  America,  it  would 
seem  that  the  sum  of  these  minor  elevations  and 
subsidences  has  produced  a  general  elevation  of  the 
edges,  and  a  general  contraction, — of  a  basin  the  long 
axis  of  which  coincides  roughly  with  the  long  axis  of 
the  Atlantic.  The  Jurassic  beds  crop  out  along  the 
outer  edge  of  the  basin,  the  cretaceous  beds  form  a 
middle  band,  while  the  tertiaries  occupy  the  troughs 
and  valleys.  All  of  these,  however,  maintain  a  cer- 
tain parallelism  determined  by  the  contour  of  the 
earlier  land  and  the  direction  of  the  older  mountain 
ridges,  to  one  another,  and  to  the  shores  of  the 
present  sea. 

From  the  parallel  of  55°  north  latitude,  at  all 
events  to  the  equator,  we  have  on  either  side  of 
the  Atlantic  a  depression  600  or  700  miles  in  width, 
averaging  15,000  feet  in  depth.  These  two  valleys 
are  separated  by  the  modern  volcanic  plateau  of  the 
A9ores.  It  does  not  seem  to  us  to  be  at  all  probable 
that  any  general  oscillations  have  taken  place  in  the 
northern  hemisphere  sufficient  either  to  form  these 
immense  abysses,  or,  once  formed,  to  convert  them 
into  dry  land. 

Reasoning  partly  upon  physical  and  partly  upon 
palaeontological  grounds,  Mr.  Prestwich  thinks  it 
probable  that  the  ancient  chalk  ocean  which  formed 
a  great  transverse  belt  entirely  across  southern  and 
eastern  Europe  and  central  Asia  on  the  one  hand,  and 
across  the  Isthmus  of  Panama  and  southern  North 
America  on  the  other,  was  cut  off  by  a  land  barrier 
from  the  Arctic  Sea,  and  on  that  account  possessed  a 


i 


CHAP.  X.]  CONTINUITY  OF  THE  CHALK.  475 

much  higher  and  more  equahle  temperature  to  the 
bottom;  and  there  is  every  reason  to  believe  that  such 
a  land  barrier  did  exist  to  the  north  of  the  great 
Atlantic  basin,  and  continuous  with  the  belt  of 
northern  land  on  which  there  is  no  deposition  of  cre- 
taceous rocks.  He  says  that  "  if  such  a  land  barrier 
existed  at  the  period  of  the  chalk,  and  that  barrier 
was  submerged  during  the  earlier  part  of  the  tertiary 
period,  it  would,  taken  in  conjunction  with  the  very 
different  conditions  of  depth  under  which  the  chalk 
and  lower  tertiaries  were  found,  go  far  to  account  for 
the  great  break  in  the  fauna  of  the  two  periods." 

Erom  the  information  we  have  as  to  the  depths 
in  the  South  Atlantic  and  the  North  Pacific,  there 
seems  to  be  no  reason,  however,  to  suppose  that  a 
barrier  has  recently  existed  shutting  off  the  polar 
sea  of  the  southern  hemisphere ;  and  I  confess  I 
cannot  quite  see  how  the  result  suggested  by  Mr. 
Prestwich  could  follow,  without  taking  into  account 
another  condition  of  whose  existence  we  seem  to 
have  evidence.  A  band  of  cretaceous  rocks  has  been 
shown  to  extend  round  the  world  a  little  to  the 
north  of  the  equator  wherever  we  have  dry  land; 
and  it  has  likewise  been  shown,  from  considera- 
tions of  depth,  that  this  chalk  band  probably  ex- 
tended also  across  our  great  ocean  basins.  At  that 
time,  then,  it  seems  that  no  continent  ranging  from 
north  to  south  interrupted  the  drift  of  the  equatorial 
current,  deflecting  the  heated  equatorial  water  to 
north  and  south  and  inducing  a  return  indraught 
of  polar  water.  This  would  undoubtedly  remove 
one  great  cause,  if  not  the  sole  cause,  of  the  present 
low  temperature  of  deep  water  between  the  tropics. 


476  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

According  to  this  view,  the  reduction  of  the  tempera- 
ture, the  cause  of  the  break  in  the  fauna,  would 
depend  more  upon  the  elevation  of  Central  America 
and  the  Isthmus  of  Panama  and  the  intertropical 
eastern  coast  of  the  continent  of  Asia,  than  even 
upon  the  depression  of  the  northern  barrier  and  the 
throwing  open  of  the  Arctic  basin. 

"If  at  any  former  period  the  climate  of  the  globe 
was  much  warmer  or  colder  than  it  is  now,  it  would 
have  a  tendency  to  retain  that  higher  or  lower  tem- 
perature for  a  succession  of  geological  epochs.  .  .  . 
The  slowness   of   climatical  change  here  alluded  to 
would  arise  from  the  great  depth  of  the  sea  as  com- 
pared with   the  height  of  the   land,   and  the   con- 
sequent lapse  of  time  required  to  alter  the  position 
of    continents   and   great   oceanic   basins.  .  .  .  The  j 
mean  height   of   the   land  is   only  1,000   feet,   the  \ 
depth  of  the  sea  15,000  feet.     The  effect,  therefore,  \ 
of  vertical   movements   equally  ].,000  feet   in  both  j 
directions,  upwards  and  downwards,  is  to  cause  a  \ 
vast  transposition   of  land  and  sea  in  those   areas 
which  are  now  continental,  and  adjoining  to  which  ^ 
there  is  much  sea  not  exceeding  1,000  feet  in  depth.  \ 
But   movements    of   equal  amount  would   have   no  \ 
tendency   to   produce   a   sensible    alteration   in   the  \ 
Atlantic  or  Pacific  oceans,  or  to  cause  the  oceanic  or  i 
continental  areas  to  change  places.     Depressions  of  \ 
1,000  feet  would  submerge  large  areas  of  existing  - 
land;  but  fifteen  times  as  much  movement  would 
be  required  to  convert  such  land  into  an  ocean  of 
average  depth,  or  to  cause  an  ocean  three  miles  deep 
to  replace  any  one  of  the  existing  continents."  ^ 

1  Lyell,  Principles  of  Geology,  1867.     Pp.  265-6.  | 


CHAP.  X.]  CONTINUITY  OF  THE  CHALK.  i'J'J 

The  wide  extent  of  Tertiaries  in  Europe  and  the 
north  of  Africa  sufficiently  proves  that  much  dry  land 
has  been  gained  in  tertiary  and  post-tertiary  times, 
and  the  great  mountain-masses  of  Southern  Europe 
give  evidence  of  great  local  disturbance.  But  al- 
though the  Alps  and  the  Pyrenees  are  of  sufficient 
magnitude  to  make  a  deep  impression  upon  the 
senses  of  men,  taking  them  together,  these  moun- 
tains would  if  spread  out  only  cover  the  surface 
of  the  North  Atlantic  to  the  depth  of  six  feet,  and 
it  w^ould  take  at  least  two  thousand  times  as  much 
to  fill  up  its  bed.  It  would  seem  by  no  means  im- 
probable, that  while  the  edges  of  what  we  call  the 
great  Atlantic  depression  have  been  gradually  raised, 
the  central  portion  may  have  acquired  an  equivalent 
increase  in  depth ;  but  it  seems  most  unlikely  that 
while  the  main  features  of  the  contour  of  the  northern 
hemisphere  remain  the  same,  an  area  of  so  vast  extent 
should  have  been  depressed  by  more  than  the  height 
of  Mont  Blanc.  On  these  physical  grounds  alone  we 
are  inclined  to  believe  that  a  considerable  portion  of 
this  area  has  been  continually  under  water,  and  that 
consequently  a  deposit  has  been  forming  there  unin- 
terruptedly, from  the  period  of  the  chalk  to  our  own. 

I  will  now  turn  to  the  palgeontological  bearings  of 
the  question.  Long  ago  Mr.  Lonsdale  showed  that 
the  white  chalk  was  mainly  made  up  of  the  cUbris  of 
foraminifera,  and  Dr.  Mantell  estimates  the  number  of 
these  shells  at  more  than  a  million  to  a  cubic  inch. 
In  1848  Dr.  Mantell,  speaking  of  the  chalk,  says 
that  it  ''forms  such  an  assemblage  of  sedimentary 
deposits  as  would  probably  be  presented  to  observa- 
tion if  a  mass  of  the  bed  of  the  Atlantic,  2,000  feet 


478 


THE  DEPTHS  OF  THE  SEA. 


[chap.  X. 


in  thickness,  were  elevated  above  the  waters  and 
became  dry  land ;  the  only  essential  diflPerence  would 
be  in  the  generic  and  specific  characters  of  the  im- 
bedded animal  and  vegetable  remains."  ^  In  1858 
Professor  Huxley  spoke  of  the  Atlantic  mud  as 
''  modern  chalk."  ^  Very  early  the  identity  of  some 
of  the  chalk  foraminifera  with  species  now  living  was 
observed.  Mr.  Prestwich,  in  his  able  resume  of  this 
question,  so  often  quoted,  gives  a  table  drawn  up  by 
Professor  Uupert  Jones  of  19  species  of  foraminifera 
out  of  110  from  the  Atlantic  mud  identical  with 
chalk  forms,  viz.  : — 


other  older  Formations  in  which 
they  are  also  found. 

: 

Species  of  Foraminifera  found  in  both  the  Atlantic 
Mud  and  the  Chalk  of  England  and  Europe. 

"""►^ 

X 
X 

X 
X 
X 

X 
X 

II 

I-? 

C3 

.1 

.    CO 

o  ^ 

X 

1 
\ 

GlanduUna  laevigata,  D'Orbigny  . 

Nodosaria  radicula,  Linn.   .     .     . 

„            raphanus,  Linn.       .     . 

Dentalina  communis,  D'Orbigny    . 

Cristellaria  cultrata,  Mont.       .     . 

,,           rotulata.  Lam.   . 

„           crepidula,  F.  and  M.  . 

Lagena  sulcata,  W.  and  J.  .     .     . 

„      globosa,  Montagu    .     .     . 

Polymorphina  lactea,  W.  and  J.    . 

.,              communis,  D'Orbigny 
,,             compressa,  D'Orbigny 
,,               orbignii,  Ehr.    .      . 
Glohigerina  hulloides,  D'Orbigny  . 
Planorbulina  lobatula,  W.  and  J. 
Pulvinulina  micheliana,  D'Orbigny 
1     Spiroplecta  biformis,  P.  and  J. 
[      Verneuilina  triquetra,  Yon  M.  .     . 
„           polystropha,  Reuss 

X 
X 
X 
X 
X 
X 

X 

X 
X 
X 
X 
X 
X 

X 



X 

_ 

1  Wonders  of  Geology,  6th  edition,  1848. 

2  Saturday  Review. 


Vol.  i. 


305. 


CHAP.    X.] 


CONTINUITY  OF  THE  CHALK. 


479 


And  the  following  table,  showing  the  number  of 
foraininifera  common  to  the  Atlantic  mud  and  various 
geological  formations  in  England  : — 


Total 
,    in  the 
i     deep 
1  Atlantic. 

Coramon  to  the  following  Formations. 

Crag. 

London 
clay. 

Chalk. 

Upper 
Jurassic. 

7 

Lower 
Jurassic. 

Rhsetic 
and 

Per. 
niian. 

Carbo- 
niferous. 

110 

53 

28 

■ 

19 

7      !      7 

i 

1 

1 

The  morphology  of  the  foraminifera  has  been 
studied  with  great  care,  and  the  difiPerences  between 
closely  allied  so-called  species  are  so  slight  that  it  is 
possible  that  in  many  cases  they  should  only  be 
regarded  as  varieties ;  but  this  careful  criticism  and 
appreciation  of  minute  differences  renders  it  all  the 
more  likely  that  the  determinations  are  correct,  and 
that  animal  forms  which  are  substantially  identical 
have  persisted  in  the  depths  of  the  sea  during  a  con- 
siderable lapse  of  geological  time. 

In  the  late  deep-sea  dredgings  by  M.  de  Pourtales 
off  the  American  coast,  and  by  H.M.  ships  '  Light- 
ning '  and '  Porcupine,'  and  Mr.  Marshall  Hall's  yacht 
'  Noma '  off  the  west  coast  of  Europe,  no  animal 
forms  have  been  discovered  belonging  to  any  of  the 
higher  groups,  so  far  as  we  are  as  yet  aware,  speci- 
ficallv  identical  with  chalk  fossils ;  and  I  do  not  think 
that  we  have  any  right  to  expect  that  such  will  be 
found.  To  a  depth  of  5,000  feet  or  so  a  large  portion 
of  the  North  Atlantic  is  at  present  heated  very  con- 
siderably above  its  normal  temperature,  while  the 
Arctic  and  Antarctic  indraught  depresses  the  bottom 


480  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

temperature  in  deep  Avater  to  a  like  extreme  degree. 
These  abnormal  temperatures  are  dependent  lipon 
the  present  distribution  of  sea  and  land;  and  I 
have  already  shown  that  we  have  evidence  of  many 
oscillations,  in  modern  times  geologically  speaking, 
which  must  have  produced  totally  different  condi- 
tions of  temperature  over  the  same  area.  Accepting, 
as  I  believe  we  are  now  bound  to  do  in  some  form, 
the  gradual  alteration  of  species  through  natural 
causes,  we  must  be  prepared  to  expect  a  total  absence 
of  forms  identical  with  those  found  in  the  old  chalk, 
belonging  to  groups  in  which  there  is  sufficient 
structural  differentiation  to  require  or  to  admit  of 
marked  variation  under  altering  circumstances.  The 
utmost  which  can  be  expected  is  the  persistence  of 
some  of  the  old  generic  types,  and  such  a  resemblance 
between  the  two  faunae  as  to  justify  the  opinion  that, 
making  due  allowance  for  emigration,  immigration, 
and  extermination,  the  later  fauna  bears  to  the 
earlier  the  relation  of  descent  with  extreme  modi- 
fication. 

I  have  already  mentioned  that  one  of  the  most 
remarkable  diflPerences  between  the  recent  Atlantic 
chalk-mud  and  the  ancient  white  chalk  is  the  total 
absence  in  the  latter  of  free  silica.  It  would  seem, 
from  the  analysis  of  chalk,  that  silicious  organisms 
were  entirely  wanting  in  the  ancient  cretaceous  seas. 
In  the  chalk  mud,  on  the  other  hand,  silica  is  found 
in  abundance,  in  most  specimens  to  the  amount  of 
from  30  to  40  per  cent.  A  considerable  portion  of 
this  is  inorganic  silica — sand;  and  its  presence  is. 
doubtless  due  to  the  circumstance  that  our  dredgings 
have  hitherto  been  carried  on  in  the  neighbourhood 


CHAP.  X.]  CONTINUITY  OF  THE  CHALK.  481 

of  land  and  in  the  path  of  sli^^it  currents,  whilst  the 
extreme  purity  of  the  white  chalk  of  Sussex  would 
seem  to  indicate  that  it  had  heen  laid  down  in  deep 
still  water  far  from  land.     A  considerable  proportion 
of  the  silica  of  the  chalk-mud,  however,  consists  of 
the  spicules  of  sponges,  of  the  spicules  and  shields 
of    radiolarians,    and   of  the    frustules  of   diatoms ; 
and    this    organic    silica   is    uniformly    distributed 
through  the  whole  mass.     Taken  in  connection  with 
the   absence   of  diffused   silica  in  the  white   chalk, 
we  have  the  singular  fact  of  the  presence  of  regular 
layers    of  flinty  masses    of   nearly  pure   silica,  pre- 
senting  frequently   the   external   form    of  more   or 
less  regularly-shaped  sponges,  and  frequently  filling 
up  the  cavities  of  sea-urchins  or  bivalve  shells.     If 
we  take  the  simple  instance  of  pure  grey  flint  filling 
up  entirely  the  cavity  of  an  urchin,  such  as   Gale- 
rites  alho-(jalerus,  or  Anancliytes  ovattis,  and  showing 
at  the  oral  opening  of  the  shell  a  little  projecting 
knob,  like  a  bullet-mould  filled  with  lead,  we  have 
no  escape  from  the  conclusion  that  after  the  death 
of  the  urchin  the  silica  has  percolated  into  the  shell 
in  solution  or  in  a  gelatinous  condition,  and  the  silica 
must  have  previously  existed  in  some  other  form, 
either  in  the  chalk  or  elsewhere.     In  the  chalk  which 
contains  not  a  trace  of  silica  we  often  find  the  moulds 
and  outlines  of  organisms  which  we  know  to  have  been 
silicious,  from  which  the  whole  of  the  silica  has  been 
removed  ;  and  I  have  more  than  once  seen  cases  in 
which  a  portion  of  the  delicate  tracery  of  a  silicious 
sponge  has  been  preserved  entire  in  a  flint,  while  the 
remainder  of  the  vase  which  projected  beyond  the 
outline  of  the  flint  appeared  in  the  chalk  as  a  trellis- 

I  I 


,482  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

work  of  spaces,  vacant,  or  loosely  filled  with  peroxide 
or  carbonate  of  iron.  It  therefore  seems  certain  that 
by  some  means  or  other  the  organic  silica,  distributed 
in  the  shape  of  sponge  spicules  and  other  silicious 
organisms  in  the  chalk,  has  been  dissolved  or  reduced 
to  a  colloid  state,  and  accumulated  in  moulds  formed 
by  the  shells  or  outer  walls  of  imbedded  animals  of 
various  classes.  How  the  solution  of  the  silica  is 
effected  we  do  not  precisely  know.  Once  reduced 
to  a  colloid  condition,  it  is  easy  enough  to  imagine 
that  it  may  be  sifted  from  the  water  by  a  process 
of  endosmose,  the  chalk  matrix  acting  as  a  porous 
medium,  and  accumulated  in  any  convenient  cavities. 
In  various  localities  in  the  chalk  and  green-sand  of 
the  North  of  England  the  peculiar  bodies  which  are 
called  Ventriculites  are  excessively  abundant,— ele- 
gant vases  and  cups  with  branching  root -like  bases, 
or  groups  of  regularly  or  irregularly  spreading  tubes, 
delicately  fretted  on  the  surface  with  an  impressed 
network  like  the  finest  lace.  In  the  year  1840  the 
late  Mr.  Toulmin  Smith  published  the  result  of 
many  years'  careful  study  of  these  bodies,  and  gave 
a  minute  and  most  accurate  description  of  their 
structure.  He  found  them  to  consist  of  tubes  of 
extreme  tenuity,  delicately  meshed,  and  having  be- 
tween them  interspaces  usually  with  very  regular 
cubial  or  octohedral  forms.  These  tubes  in  the  Ven- 
triculites found  in  chalk  were  empty,  or  contained  a 
little  red  ochreous  matter ;  but  when  a  ventriculite  or 
a  portion  of  one  happened  to  be  entangled  in  a  flint,  it 
was  either  incorporated  with  the  flint  or  replaced  by 
silica.  Mr.  Toulmin  Smith  supposed  that  the  skeleton 
of  the  ventriculite   had  been   originally  calcareous, 


I 


X.] 


CONTINVITY  OF  THE  CHALK. 


483 


and  he  referred  the  group  to  the  Polyzoa.  When 
Mr.  Toulmin  Smith  studied  the  Ventriculites,  the 
Hexactinellidae — the  sponges  with  six-rayed  meshes 
or  spicules — were  practically  unknown,  though  there 


Fig.  f>,(i.— Ventriculites  simplex,  Toulmin  Smith.    Once  and  a  half  the  natural  size. 


were  already  a  few  examples  in  museums.  One  of  the 
first  results  of  deep-sea  dredging  was  the  discovery 
that  the  chalk-mud  of  the  deep  sea  is  in  many  places 
literally  crowded  with  these  ;   and  when  we  compare 

II  2 


484  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

such  recent  forms  as  Aphrocallistes,  Iphiteon,  Sol- 
tenia,  and  AsJconema  with  certain  series  of  the  chalk 
Ventriculites,  there  cannot  be  the  slightest  doubt  that 
they  belong  to  the  same  family— in  some  cases  to 
very  nearly  allied  genera.  Pig.  80  represents  a  very 
beautiful  specimen  of  Ventriculites  simplex  preserved 
in  flint,  for  which  I  am  indebted  to  Mr.  Sanderson  of 
Edinburgh.  Looking  at  this  in  the  light  of  our 
knowledge  of  Euplectella  or  ApJirocallistes  beatrix, 
we  have  no  difficulty  in  working  out  its  structure, 
even  to  the  most  minute  microscopic  detail. 

Other  sponges,  belonging  chiefly  to  the  Lithistidse 

and  the  Corticatse,  re- 
produce with  wonderful 
accuracy  the  more  irre- 
gular sponge-forms  of 
the  chalk  and  green- 
sand  ;  and  a  group,  as 
yet  undescribed,  but 
apparently  an  aberrant 
family  of  the  Esperiadse, 
send   out   long   delicate 

Fig.  ^\.— Ventriculites  simplex,  Toui-min  Smith.     tUbCS,        WlllCn        COUtraCt 
Outer  surface ;  four  times  the  natural  size.  i  •     i  xi  i       i.      *  j. 

slightly,  but  m  a  most 
characteristic  way,  at  the  point  of  their  insertion 
into  the  sponge  body,  recalling  very  forcibly  the 
peculiar  manner  in  which  the  tube-like  root  processes 
join  the  sponge  in  such  genera  as  the  vaguely  defined 
Choanites. 

One  sponge  belonging  to  the  group  is  represented 
at  Eig.  83.  A  sphere  15  to  20  mm.  in  diameter  con- 
sists of  a  smooth  glossy  external  rind,  composed  of 
closely  meshed  pin-headed  spicules,  with  two  kinds 


CHAP.    X.] 


CONTINUITY  OF  THE  CHALK. 


485 


of '  spicules  of  the  sarcode/  one  large,  C-shaped,  the 
other  much  more  minute,  answering  to  Bowerbank's 
'  tridentate  equianchorate '  type ;  every  now  and  then 


^^^i^*% 


Mrmrmr 


Fig.  ^2.— Ventriculites  simplex,  Toulmin  Smith.     Section  of  the  outer  wall,  showing  the 
structure  of  the  silicious  network,    (x.  50.) 

the  rind  thus  formed  coming  to  the  margin  of  a  small 
pore.  The  interior  of  the  sphere  is  filled  with  soft 
semi-fluid  sarcode,  supported  by  the  loosest  possible 


Fig.  83.— CcB?osj>7icRm  tuUfecr.,  Wvville  Thomson.    Slightly  enlarged.   Off  the  coa.st  of  Portugal. 

mesh-work  of  granular  horny  matter  and  pin- 
headed  spicules.  Erom  points  apparently  irregularly 
placed  on  the  surface  of  the  sponge,  tubes  about 
3  mm.  in  diameter  run  out  in  all  directions; 
the  walls  of  the  tubes  are  thin  and  delicate,  being 


486  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

more  so  towards  the  distant  ends,  where  the  tubes 
contract  slightly  to  an  open  orifice.  At  the  proximal 
end,  at  the  junction  between  the  tube  and  the 
sponge  body,  there  is  also  a  contraction,  and  a  slight 
pit-like  involution  of  the  surface  of  the  sponge. 
There  is  something  very  characteristic  in  tliis  pecu- 


ViQ.  M.—' Choanites.'    In  a  flint  from  the  white  chalk. 

liar  form  of  junction  which  it  is  not  easy  to  define, 
but  which  almost  forces  the  conviction  that  there  is 
the  closest  relation  between  these  recent  forms  and 
tube-bearing  fossil  sponges  such  as  Choanites. 

Professor  Martin  Duncan  mentions  several  corals 


CHAP.  X.]  CONTINUITY  OF  THE  CHALK,  487 

from  the  coast  of  Portugal  more  nearly  allied  to 
chalk  forms  than  to  any  others,  but  it  is  in  the 
Echinodermata  that  the  peculiar  relation  between 
the  ancient  and  the  modern  faumje  becomes  most 
apparent.  To  review  briefly  the  chief  points  bearing 
upon  this  question.  The  Apiocrinidse,  the  group  of 
fixed  crinoids  which  I  have  already  described,  are 
abundant  throughout  the  whole  range  of  the  Jurassic 
rocks,  their  remains  being  frequently  very  abundant 
in  the  thick  cream-coloured  limestone  beds  of  the 
oolites.  Towards  the  close  of  the  Jurassic  period, 
the  typical  genera  disappear,  and  in  the  chalk  we 
find  the  group  represented  by  an  evidently  degenerate 
form,  Bourguetticmms,  In  some  tertiary-beds  frag- 
ments of  the  stems  of  a  small  Bourguetticrinus  have 
been  found,  and  such  were  likewise  discovered  in 
the  recent  lime  breccia  of  Guadaloupe,  which  con- 
tained the  well-known  human  skeleton  now  in  the 
British  Museum.  There  can  be  little  doubt  that 
these  tertiary  and  post-tertiary  fragments  are  to  be 
referred  rather  to  the  genus  Rhizocrinus,  which  we 
now  know  to  be  so  widely  distributed,  living,  in 
deep  water.  Now  in  this  series  of  Apiocrinidse, 
extending  from  the  Eorest  marble  to  the  present 
time,  although  there  is  a  succession  of  constantly 
changing  species,  yet  the  gradual  degradation  in 
development  in  the  same  direction  throughout  the 
series  seems  to  point  unmistakeably  to  some  form 
of  continuity,  to  a  type  gradually  succumbing  to  con- 
ditions slowly  altering  in  an  unfavourable  direction. 

The  other  family  of  the  stalked  crinoids,  the 
Pentacrinidse,  are  in  a  different  position.  They  are 
abundant  in  the  Lias ;  very  abundant  in  the  lower 


488  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

oolite,  where  slabs  are  often  found  almost  made  up 
of  them,  with  a  characteristic  deep-water  association 
of  CldariSy  Astrogonkim,  and  Astropecten ;  and  al- 
though not  abundant  in  the  English  chalk,  several 
species  are  found,  and  these  show  no  tendency  to 
degeneracy.  As  might  be  expected,  such  remains 
are  rare  in  the  shallow-water  tertiaries.  With  regard 
to  their  distribution  in  modern  seas,  from  the 
apparent  abundance  of  P.  asteria  and  P.  mulleri 
in  deep  water  in  the  West  Indies,  and  of  P.  u^ymlle- 
tJiomsoni  off  the  coast  of  Portugal,  it  is  very  pos- 
sible, as  I  have  already  said,  that  they  may  occupy 
a  much  more  important  place  in  the  abyssal  fauna 
than  we  at  present  imagine. 

Nearly  all  the  additions  from  the  deep  water  to 
the  list  of  the  Asteridea  fall  into  the  genera 
Archaster  and  Astropecten,  or  into  the  various  sub- 
divisions of  the  old  genus  Goniaster.  Prom  their 
breaking  up  into  a  multitude  of  uu  distinguishable 
ossicles  by  the  decomposition  of  their  soft  organic 
matter  immediately  after  death,  the  fossil  remains 
of  star-fishes  are  comparatively  rare,  and  are  scarcely 
met  with  except  in  fine  calcareous  formations,  such 
as  the  Wenlock  limestone, — and  in  later  times  in  the 
fine  vellow  limestones  of  the  oolites,  and  in  the 
white  chalk.  In  the  latter  formation,  deposited  ap- 
parently  very  much  under  the  same  circumstances 
as  the  Atlantic  chalk-mud,  the  general  character  of 
the  group  of  imbedded  star-fishes  is  almost  the  same 
as  in  the  modern  fauna  of  the  deep  Atlantic. 

The  Echinidea  are  a  more  typical  order.  Erom 
the  compactness  of  their  tests  they  are  more  readily 
preserved  entire,  and  from  the  earliest  periods  their 


CHAP.  X.]  CONTINUITY  OF  THE  CHALK.  489 

characteristic  and  harmoniously  varying  series  are 
of  considerable  value  in  the  discrimination  of  the 
different  formations.  In  the  soft  white  chalk  of  the 
south  of  England  their  remains  are  extremely  abun- 
dant. Perhaps  the  most  abundant  and  characteristic 
fossils  in  the  chalk  are  the  Cidaridse,  and  these  more 
than  any  other  chalk  fossils  illustrate  the  peculiar 
conditions  under  which  the  chalk  has  been  laid  down. 
The  great  spines  of  Cidaris  are  attached  to  the  plates 
of  the  shell  by  a  central  ligament  which  passes  from 
the  cup  on  the  spine  to  a  perforation  in  the  ball  on 
the  plate,  and  by  a  membrane  which  rises  from  the 
plate  and  passes  over  the  base  of  the  spine.  The 
spines  are,  however,  so  disproportionately  large,  and 
the  soft  matter  softens  and  decomposes  so  rapidly 
after  death,  that  it  is  diflicult  to  keep  the  spines 
attached  to  a  specimen  prepared  even  with  consider- 
able care.  In  the  chalk,  tests  of  Cidaris  are  fre- 
quently preserved  absolutely  entire,  with  all  the 
spines  in  position ;  so  that  by  carefully  working  out 
the  chalk  with  a  penknife,  we  can  here  have  the 
whole  animal  perfect.  It  is  difficult  to  see  precisely 
how  this  result  can  have  been  produced.  The  urchin 
must  have  sunk  into  the  soft  chalk-mud  and 
been  covered  up  by  a  sufficient  quantity  to  support 
its  spines  and  test,  and  allow  the  whole  to  become 
gradually  compacted  into  a  solid  mass.  One  of  the 
new  deep-sea  Cidarites  belongs  to  a  genus  which 
had  previously  been  supposed  to  be  extinct,  but  the 
chalk-mud  forms  generally  do  not  show  any  special 
approach  to  any  particular  chalk  species.  Still  the 
general  character  of  the  group  is  the  same.  The 
Echinothuridse  were  previously  known  only  as  chalk 


490  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

fossils,  SO  that  their  presence  apparently  in  abun- 
dance in  the  recent  chalk-mud  is  a  clear  instance 
of  the  preservation  of  one  of  the  old  types  hitherto 
supposed  to  be  extinct.  The  same  may  be  said  of 
Poiirtalesia,  which  must  associate  itself  either  with 
Ananchytes  or  with  Dysaster,  both  of  which  are 
types  of  groups  likewise  supposed  to  have  been  lost. 
We  thus  find  that,  while  no  Echinoderm  hitherto 
discovered  in  the  deep  water  is  specifically  identical 
with  any  chalk  form,  not  only  does  the  abyssal  fauna 
with  its  abundance  of  the  Cidaridee,  Echinothuridae, 
and  irregular  urchins,  and  the  disproportionate  num- 
bers of  the  genera  Astropecten^  Astrogonlum,  and 
Stellaster,  and  their  allies  among  starfishes,  singu- 
larly resemble  the  chalk  in  general  facies ;  but 
several  genera  approach  chalk  forms  more  closely 
than  they  do  any  hitherto  known  in  a  living  state 
— approach  them  so  closely  as  almost  to  force  upon 
us  the  conviction  that  their  relation  is  one  of  descent, 
accompanied  by  change  of  conditions  and  consequent 
modification,  though  not  to  any  extreme  degree. 

As  I  have  already  stated,  the  whole  of  the  mol- 
lusca  from  the  deep  water  which  had  been  previously 
described  as  fossils  were  known  from  tertiary  and 
post-tertiary  beds ;  with  the  very  doubtful  exception 
of  our  common  Terehratulina  caput-serpentis^  which 
certainly  approaches  very  closely  Terebratula  striata 
from  the  chalk. 

It  is  not  surprising  that  this  should  be  the  case. 
It  is  a  marked  character  of  the  European  Tertiaries 
that  with  the  exception  of  some  of  the  older  beds  in 
the  south  of  Europe,  all  of  them  have  been  deposited 
in  shallow  water ;  so  that  the  tertiary  beds  represent 


CHAP.  X.]  CONTINUITY  OF  THE  CHALK.  491 

the  mineral  accumulations  and  the  fauna  of  the 
margin  of  some  sea.  We  may  say  that  they  have  been 
deposited  in  the  shallow  water  of  tertiary  seas  whose 
deep-sea  fauna  is  unknown,  and  this  mode  of  expres- 
sion is  most  in  accordance  with  previous  ideas ;  but  if 
the  view  here  advocated  be  correct,  we  must  regard 
the  tertiaries  as  the  deposits  formed  and  exposed  by 
depressions  and  upheavals  of  the  borders  of  the  cre- 
taceous sea ;  of  a  sea  which,  with  many  changes  of 
condition  produced  by  the  same  oscillations  which 
alternately  exposed  and  submerged  the  tertiaries, 
existed  continuously,  depositing  conformable  beds  of 
chalk-mud  from  the  period  of  the  ancient  chalk. 

MoUusca  are  chiefly  shallow-water  forms,  although 
some  of  them  are  special  to  deep  water,  and  others 
have  a  great  vertical  range.  As  I  have  already  said, 
considering  the  many  changes  in  the  conditions  which 
most  affect  animal  life  which  have  occurred  during 
later  geological  times,  we  cannot  expect  to  find  any 
animals  of  the  higher  groups  specifically  identical 
with  chalk  fossils ;  the  difficulty  in  the  case  seems 
rather  to  be  to  account  for  the  identity  of  many 
living  deep-water  species  with  species  found  in  the 
Tertiaries.  I  think,  however,  that  we  can  find  a  clue. 
Most  of  the  species  common  to  the  modern  Atlantic 
and  to  tertiary  beds  are  now  found  in  the  Atlantic  at 
much  greater  depths  than  those  at  which  they  were 
imbedded  in  the  tertiary  seas.  This  we  know  by  the 
species  from  shallower  water  which  are  associated 
with  them  in  the  Tertiaries.  They  are,  therefore, 
species  which  had  a  considerable  vertical  range ;  and 
probably  while  many  of  the  shallower  water  forms 
were    exterminated   by  elevations   or   other   change 


492  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

affecting  the  first  one  or  two  hundred  fatlioms,  they 
were  enabled  to  survive,  the  deeper  part  of  their 
habitat  having  suffered  but  little  alteration. 

Sir  Charles  Lyell  says :  "  The  reader  should  be 
reminded  that  in  geology  we  have  been  in  the  habit 
of  founding  our  great  chronological  divisions,  not  on 
foraminifera  and  sponges,  nor  even  on  echinoderms 
or  corals,  but  on  the  remains  of  the  most  highly 
organized  beings  available  to  us,  such  as  moUusca. 
...  In  dealing  with  the  mollusca,  it  is  those  of  the 
highest  or  most  specialized  organizations  which  afford 
us  the  best  characters  in  proportion  as  their  vertical 
range  is  the  most  limited.  Thus  the  cephalopoda  are 
the  most  valuable,  as  having  a  more  restricted  range 
in  time  than  the  gasteropoda,  and  these  again  are  more 
characteristic  of  the  particular  stratigraphical  sub- 
divisions than  the  lamellibranchiate  bivalves,  while 
these  last  again  are  more  serviceable  in  classification 
than  the  brachiopoda,  a  still  lower  class  of  shell-fish, 
which  are  the  most  enduring  of  all."  With  great 
deference  to  Sir  Charles  Lyell,  I  cannot  regard  the 
most  highly  specialized  animal  groups  as  those  most 
fitted  to  gauge  the  limits  of  great  chronological 
divisions,  though  I  admit  their  infinite  value  in 
determining  the  minor  subdivisions. 

Tiie  culmination  of  such  animal  groups,  such  as 
we  find  in  the  marvellous  abundance  and  variety  of 
both  orders  of  cephalopods  at  the  end  of  the  Jurassic 
and  the  commencement  of  the  cretaceous  period, 
undoubtedly  brings  into  high  relief,  and  admirably 
illustrates  to  the  student,  the  broad  distinctive  cha- 
racters of  the  mezozoic  fauna ;  but  speaking  very 
generally,   the  more  highly  a  mollusc  is  specialized 


CHAP.  X.]  CONTINUITY  OF  THE  CHALK.  493 

the  shallower  is  the  water  which  it  inhabits.  The 
cephalopods  are  chiefly  pelagic  and  surface  things, 
and  their  remains  are  consequently  found  in  deposits 
from  all  depths.  To  this  general  pelagic  distri- 
bution of  cephalopods  there  seem  to  he  two  re- 
markable exceptions,  and  these  the  two  members 
of  their  class  which  are  by  far  the  most  interest- 
ing in  their  geological  relations.  Nautilus  pom- 
pilius  inhabits  the  deep  water  of  the  Pacific,  while 
the  habitat  of  Spirula  australis  is  unknown.  The 
shell  of  Spirula  is  thin  and  light,  and,  probably 
after  the  death  of  the  animal  and  by  the  decom- 
position of  organic  matter,  it  becomes  filled  with  air, 
aod  the  emptied  shell  floats,  and  is  drifted  along  on  the 
surface  of  the  sea.  Tropical  shores  are  strewn  with 
the  pearly  little  coil,  which  attracts  attention  by  the 
elegance  of  its  form.  It  is  abundant  on  all  shores  in 
the  path  of  the  Gulf-stream.  Sysselmann  Mliller  gave 
me,  a  few  years  ago,  a  quantity  which  had  been  drifted 
on  the  south-western  shores  of  different  islands  of  the 
Fseroe  group.  Still  the  structure  of  the  animal  of 
Spirula  may  be  said  to  be  unknown.  One  specimen 
only,  which  was  described  by  Professor  Owen,  was 
found  nearly  perfect  on  the  coast  of  New  Zealand  by 
Mr.  Percy  Noel.  I  suppose  there  can  be  little  doubt 
that  this  is  a  deep-water  form,  and  I  hope  that  with 
our  deep-sea  dredging  we  shall  soon  clear  up  its 
economy ;  but  in  the  meantime  the  evident  abundance 
of  the  animal  and  our  ignorance  of  its  history  are  very 
suggestive.  In  the  London  clay  one  or  two  examples 
of  a  fossil  have  been  found,  nearly  allied  to  Spirula, 
but  differing  in  this  respect — that  a  solid  conical 
rostrum  projects    backwards,  its  half-calcified,  half- 


494  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

horny  substance  enclosing  the  greater  part  of  the 
curved  spiral  shell.  Now  if  the  recent  Spirula  had 
been  weighted  with  such  a  rostrum  it  would  probably 
have  remained  up  to  the  present  time  utterly  unknown 
to  us.  It  is  unwise  to  prophesy,  but  I  certainly 
look  upon  some  form  allied  to  Spirulirostris  as  one 
of  the  most  likely  spoils  of  the  deep  sea.  From  the 
Tertiaries  we  pass  to  the  Cretaceous  forms,  and  find 
in  Belemnitella  the  chambered  shell  straightened  and 
reduced,  and  the  '  guard '  greatly  increased  in  size. 
If  Belemnites  were  deep-sea  animals,  as  seems  very 
probable,  and  if  any  of  them  still  exist, — from  the 
form  and  weight  of 'their  shells  it  is  scarcely  possible 
that  they  should  ever  be  thrown  up  on  the  shore, 
and  without  deep-sea  dredging  they  might  remain 
for  ever  unknown.  I  merely  mention  this  to  show 
that  it  is  by  no  means  safe  to  base  even  what  little 
argument  might  rest  upon  it,  upon  the  absence 
at  the  present  time  of  all  representatives  of  the 
cretaceous  cephalopodous  fauna. 

The  gasteropods,  with  comparatively  few  excep- 
tions, range  from  the  shore  to  a  depth  of  100  to 
200  fathoms,  and  lamellibranchs  become  scarcer  at 
a  slightly  greater  depth ;  while  some  orders  of  bra- 
chiopods,  Crustacea,  echinoderms,  sponges,  and  fora- 
minifera,  descend  in  scarcely  diminished  numbers  to 
a  depth  of  10,000  feet.  In  fact,  the  bathymetrical 
range  of  the  various  groups  in  modern  seas  corre- 
sponds remarkably  with  their  vertical  range  in 
ancient  strata. 

A  change  in  the  distribution  of  sea  and  land  in- 
volving a  mere  change  in  the  course  of  an  ocean- 
current  might  modify  the  conditions  of  an  area  for 


CHAP.  X.]  CONTINUITY  OF  THE  CHALK.  495 

most  cephalopods  and  all  pteropods,  heteropods,  and 
other  surface  living  animals  of  high  type,  even  to 
their  extinction.  By  oscillations  of  500  feet  up  or 
down,  the  great  mass  of  gasteropods,  and  all  reef- 
building  corals,  would  be  forced  to  emigrate,  would 
become  modified,  or  would  be  destroyed, — and  another 
hundred  fathoms  would  exterminate  the  greater  num- 
ber of  bivalves ;  w^hile  elevations  and  depressions  to 
ten  times  that  amount  might  only  slightly  affect  the 
region  of  brachiopods,  echinoderms,  and  sponges. 

After  a  careful  consideration  of  the  results  of  recent 
investigations,  we  are  strengthened  in  our  confidence 
in  the  truth  of  the  opinion  which  we  previously  held, 
that  the  various  groups  of  fossils  characterizing  the 
tertiary  beds  of  Europe  and  North  America  represent 
the  constantly  altering  fauna  of  the  shallower  por- 
tions of  an  ocean  whose  depths  are  still  occupied  by 
a  deposit  which  has  been  accumulating  continuously 
from  the  period  of  the  pre-tertiary  chalk,  and  w^hich 
perpetuates  with  much  modification  the  pre-tertiary 
chalk  fauna.  I  do  not  see  that  this  view  militates  in 
the  least  against  the  "  reasoning  and  classification"  of 
that  geology  which  we  have  learned  from  Sir  Charles 
Lyell ;  our  dredgings  only  show  that  these  abysses  of 
the  ocean — abysses  which  Sir  Charles  Lyell  admits  in 
the  passage  quoted  above,  to  have  outlasted  on  account 
of  their  depth  a  succession  of  geological  epochs — are 
inhabited  by  a  special  deep-sea  fauna,  possibly  as  persis- 
tent in  its  general  features  as  the  abysses  themselves. 
I  have  said  at  the  beginning  of  this  chapter,  that  I 
believe  the  doctrine  of  the  'continuity  of  the  chalk,' 
as  understood  by  those  who  first  suggested  it,  now 
meets  with  very  general  acceptance  ;  and  in  evidence 


496  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

of  this  I  will  quote -two  passages  in  two  consecutive 
anniversary  addresses  by  Presidents  of  the  Geological 
Society,  and  we  may  have  every  confidence  that  the 
statements  of  men  of  so  great  weight,  made  under 
such  circumstances,  indicate  the  tendency  of  sound 
and  judicious  thought.  Professor  Huxley,  in  the 
anniversary  address  for  the  year  1870,  says  : — "  Many 
years  ago^  1  ventured  to  speak  of  the  Atlantic  mud 
as  '  modern  chalk,'  and  I  know  of  no  fact  inconsistent 
with  the  view  which  Professor  Wyville  Thomson  has 
advocated,  that  the  modern  chalk  is  not  only  the 
lineal  descendant,  so  to  speak,  of  the  ancient  chalk, 
but  that  it  remains,  so  to  speak,  in  possession  of  the 
ancestral  estate  ;  and  that  from  the  cretaceous  period 
(if  not  much  earlier)  to  the  present  day,  the  deep  sea 
has  covered  a  large  part  of  what  is  now  the  area  of 
the  Atlantic.  But  if  Glohlgerina  and  Terehratula 
caput-serpentis  and  Beryx,  not  to  mention  other 
forms  of  animals  and  of  plants,  thus  bridge  over  the 
interval  between  the  present  and  the  mezozoic 
periods,  is  it  possible  that  the  majority  of  other 
living  things  underwent  a  sea-change  into  something 
new  and  strange  all  at  once  ?  " 

And  Mr.  Prestwich,  in  the  presidential  address  for 
1871,  says  : — "Therefore,  although  I  think  it  highly 
probable  that  some  considerable  portion  of  the  deep 
sea-bed  of  the  mid- Atlantic  has  continued  submerged 
since  the  period  of  our  chalk,  and  although  the  more 
adaptable  forms  of  life  may  have  been  transmitted  in 
unbroken  succession  through  this  channel,  the  im- 
migrations of  other  and  more  recent  faunas  may 
have  so  modified  the  old  population,  that  the  original 

^  Saturday  Review,  1858  :    "  Chalk,  Ancient  and  Modern."        - 


CHAP.  X.J  CONTINUITY  OF  THE  CHALK.  497 

chalk  element  is  of  no  more  importance  than  is  the 
original  British  element  in  our  own  English  people.'* 

Mr.  Prestwich  thus  fully  admits  the  high  pro- 
bability of  the  '  continuity '  for  which  we  contend. 
The  last  question  which  he  raises  in  the  sentence 
quoted  is  one  of  enormous  difficulty,  which  we  have 
as  yet  no  data  to  solve.  It  is  perhaps  not  very  much 
harder,  however,  after  all^  than  the  problem  in  ethno- 
logy which  he  has  selected  as  an  illustration. 

Several  other  very  important  questions  bearing 
upon  the  conditions  of  the  ocean  at  great  depths, 
occupied  the  attention  of  the  naturalists  in  scientific 
charge  of  the  dredging  cruises  of  the  'Lightning' 
and  '  Porcupine.'  An  assistant  versed  in  the  methods 
of  chemical  and  physical  research  accompanied  the 
vessel  on  each  occasion.  A  son  of  Dr.  Carpenter, 
Mr.  William  Lant  Carpenter,  B.A.,  B.Sc,  went  on 
the  first  cruise  with  Mr.  Jeffreys.  Mr.  John  Hunter, 
P.C.S.,  a  promising  young  chemist,  since  deceased, 
accompanied  me  to  the  Bay  of  Biscay,  and  Mr.  Her- 
bert Carpenter,  a  younger  son  of  my  colleague,  was 
our  companion  during  the  third  long  cruise  in  the 
Paeroe  channel. 

The  specific  gravity  of  the  water  was  taken  at 
each  station,  and  in  the  serial  soundings  the  water- 
bottle  was  let  down  to  the  intermediate  depths  and 
'  the  water  carefully  tested.  The  differences  observed 
were  very  slight,  but  they  were  as  a  rule  confirmatory 
of  Professor  Eorschammer's  opinion  that  Arctic  water 
contains  less  salt  than  the  sea-water  of  temperate 
and  intertropical  regions. 

As  I  have  already  mentioned  (page  46),  organic 
natter  in  appreciable  quantity  was  detected  by  the 

K  K 


498  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

permanganate  test  everywhere,  and  at  all  depths. 
The  gas  contained  in  the  water  was  carefully  ana- 
lysed, and  it  was  found,  as  a  general  result,  that 
the  amount  of  free  carbon  dioxide  increased  and 
the  proportion  of  oxygen  diminished  with  increased 
depth.  There  seemed  to  be  reason  to  believe,  how- 
ever, that  the  quantity  of  carbon  dioxide  depended 
to  a  great  degree  upon  the  abundance  of  the  higher 
forms  of  life.  Mr.  Lant  Carpenter  used  always  to 
predict  a  bad  haul  for  the  zoologists  When  he  found 
the  proportion  of  carbon  dioxide  to  the  oxygen  and 
nitrogen  unusually  low.  The  great  increase  in  the 
quantity  of  carbon  dioxide  was  just  above  the  bottom. 
The  general  average  of  thirty  analyses  of  surface- 
water  gives  the  following  as  the  proportions  of  the 
contained  gases  present: — Oxygen  25*1,  nitrogen  54-2, 
carbon  dioxide  20*7  ;  this  proportion  was  subject, 
however,  to  great  variations.  Intermediate  water 
gave  an  average  percentage  of  oxygen  22*0,  nitrogen 
52 '8,  and  carbon  dioxide  26*2  ;  while  bottom  waters 
gave — oxygen  19*5,  nitrogen  52*6,  and  carbon  dioxide 
27 '9.  But  bottom  water,  at  a  comparatively  small 
depth,  often  contained  as  much  carbon  dioxide  as 
intermediate  water  at  much  greater  depths.  In  one 
of  the  serial  soundings,  in  which  the  water  was 
taken  at  every  50  fathoms,  three  analyses  gave  the 
following  singular  result : — 

T50  Fathoms.  800  Fathoms.  Bottom,  862  Faths. 

Oxygen 18-8  17-8  '  17-2 

Mtrogen     ....     49-3     .  48-5  34-5 

Carbon  dioxide     .     .     31-9  33-7  48-3 

The  greatly  increased  percentage  of  carbon  dioxide 
in  the  stratum  of  sea-water  immediately  overlying 


CHAP.  X.]  CONTINUITY  OF  THE  CHALK.  499 

the  sea-bed,  was  here  accompanied  by  a  great  abun- 
dance of  animal  life. 

I  can  scarcely  regret  that  the  space  at  my  disposal 
will  not  allow  me  to  enter  at  present  into  the  many 
very  important  bearings  of  these  physical  investiga- 
tions, for  I  am  compelled  to  admit  that  I  do  not 
place  thorough  confidence  in  our  results.  The  obser- 
vations and  analyses  were  undoubtedly  conducted 
with  greaV  care  and  skill,  but  the  difference  between 
different  samples — in  specific  gravity,  and  more  espe- 
cially in  chemical  composition  and  the  relative  pro- 
portion of  the  ingredients — is  so  very  slight,  that  more 
exact  methods  than  those  which  have  been  hitherto 
employed  will  be  required  to  insure  accurate  results. 

In  such  investigations  everything  depends  upon 
the  perfection  of  the  means  of  bringing  up  water 
from  any  given  depth ;  and  the  principle  of  the 
construction  of  the  water-bottle  used  in  the  *  Por- 
cupine '  was  faulty.  It  consists  of  a  strong  tube  of 
brass  about  two  feet  in  length  and  two  inches  in 
internal  diameter,  containing  rather  more  than  a 
litre  and  a  half,  and  closed  at  each  end  by  a  brass 
disk.  In  the  centre  of  each  of  these  disks  there 
is  a  round  aperture  closed  by  a  well-ground  conical 
valve,  both  valves  opening  upwards  when  the  instru- 
ment is  in  position  for  being  let  down. 

In  passing  down  through  the  water,  a  continuous 
current  is  supposed  to  raise  the  valves  and  run 
through  the  bottle,  thus  keeping  it  constantly  filled 
with  the  water  of  the  layer  through  which  it  is 
passing.  On  reversing  the  motion  in  hauling  up, 
the  valves  fall  into  their  places,  and  the  contents 
of  the   tube  at  the  greatest   depth    are   brought  to 

KK  2 


500  THE  DEPTHS  OF  THE  SEA.  [chap.  x. 

the  surface.  This  bottle  appeared  to  answer  fairly, 
and  we  often  had  evidence,  from  its  turbidity,  that 
bottom-water  came  up  ;  but  subsequent  experiments 
have  shown  that  it  cannot  be  depended  upon,  and 
some  of  the  reasons  are  sufficiently  obvious.  The 
instrument  will  not  work  at  all  unless  the  descend- 
ing motion  be  sufficiently  steady  and  rapid  to  main- 
tain a  current  capable  of  keeping  two  heavy  brass 
valves  open  to  their  full  extent;  if  there  be  the 
slightest  reversal,  or  jerk,  or  irregularity  in  hauling 
up,  the  water  is — at  all  events  partially — changed  ; 
the  two  valves,  even  when  thoroughly  open,  are 
directly  in  the  path  of  the  ingress  and  egress  of 
the  water — and  there  is  reason  to  believe  that  the 
water  is  not  so  rapidly  and  thoroughly  changed  as 
we  at  first  imagined.  A  perfectly  satisfactory  water- 
bottle  is  still  a  desideratum,  but  I  believe  that  one 
which  was  used  by  Dr.  Mayer  and  Dr.  Jacobsen 
in  the  German  North  Sea  expedition  of  the  past 
summer,  goes  far  to  remedy  most  of  these  defects. 
I  hope  we  may  be  in  a  better  position  to  give  an 
opinion  a  year  hence. 

I  give,  in  the  appendix  to  this  chapter,  an  abstract 
of  the  general  results  of